Creates a new (hidden) flutter command 'ide-config' that will create and/or update
existing .iml files and some files under the .idea directory, as well as
removing existing *.iml files and the .idea directory.

It also:

 * Adds *.iml to the .gitignore
 * Removes existing .iml files from the repo, and moves them to the
   packages/flutter_tools/ide_templates/intellij directory.
 * Adds a flag to ide-config ('--update-templates') that will take any new .iml
   files in the flutter tree and add them to the existing templates.
     - If --overwrite is also specified, then all existing templates will also
       be overwritten with the contents from the flutter tree, and any that have
       been deleted from the flutter tree will also be removed from the
       templates.
 * Added new run configurations for all existing app targets that will now also
   be automatically added to IntelliJ.
 * Setting up the environment also includes setting the coding style guidelines
   and the git VCS.
 * Note that after this PR lands, Flutter developers will need to run it once to
   re-create the .iml files and configuration files that have been removed.

After this PR lands, .iml files will no longer appear in the untracked files
section for git.

* Revert "Revert "fix --force-upgrade script; upgrade to the latest package versions (#12700)" (#12729)"

This reverts commit 7f0d4f4c.

* keep linter pinned at 0.1.35

This reverts commit 5b357500.

* fix updrade script; upgrade to the latest package versions

* exclude special dependencies from transitive closure

* fix stack trace handling in flutter_test due to stack_trace change

* change type on _emptyStackTrace

* Force upgrade update packages with improved update process.

* Update packages

* Revert "Update packages"

This reverts commit a37de26d3f4f7f5a15746ff791002625faa3d3c0.

* Add framework-side support for system text scale factor.

* Rolling engine to e3404b81a53ba3180c7623a6f2190ebb28518f30
  Additional changes rolled in with engine change:
    libtxt: implementation of GetRectsForRange that processes a line at a time - e3404b8
    Provide an entropy source to the Dart engine (#4161) - e1aa867
    libtxt: search for fallback fonts that can match emoji and CJK characters - 8061df1
    Roll skia to e4679fa06a. (#4157) - 267e7a8
    Update buildroot to 53fea9aebbcc39c6522731471a1a45960ee0685e (#4160) - 02ea7ae
    Revert engine Dart roll. (#4158) - 14aab33
    Add support for system text scale factor. (#4124) - b2a7f4b
    Include _http into sky_engine libraries for analyzer (#4154) - b930f10
    libtxt: Remove postprocess_line and improve tracking of X offsets - 86f95f0
    libtxt: remove redundant line_widths (#4152) - 14bf515
    Roll dart to ade37f931e90b0fdb8fe16d6bf6f089545da55b6 (#4151) - 6f1264f

* Pin all dependencies ONCE AND FOR ALL

This replaces the secret `flutter update-packages --upgrade` with a destructive `flutter update-packages --force-upgrade` that actually goes and pins every dependency and transitive dependency in every flutter package to the same version.

* Add comments.

Under android/ directory, ignore:
GeneratedPluginRegistrant.java

Under ios/ directory, ignore:
GeneratedPluginRegistrant.h
GeneratedPluginRegistrant.m
Pods/

* Roll android build tools to 25.0.3

* Roll android build tools to 25.0.3 in templates

This reverts commit 5ed2984e.

This ensures that when someone opens the project using IDEA,
the Flutter plugin will find the location of the Flutter SDK
and run "flutter packages get".

Remove checked in .lock, remove checked in cocoapods scripts in xcode project, let the automated test run pod install specifically for this test

* Remove Pods dir from layers example

* Remove Pods dir from flutter_view example

* Add Pods cache dir to ios/.gitngnore

* Add missing ending newlines

Follow-up from #9422

Aggressively apply the const lint.

* Make IntelliJ metadata files consistent with the current flutter create template

* Add missing IJ files from current flutter create template

* Remove run config from layers as it requires running with -t

* Remove workspace.xml files per review feedback

Gradle projects are evaluated in lexicographical order, and the plugin
projects are at the same level as the :app project, so if a plugin has
a name that comes before 'app' (like, for example, any name that starts
with a capital letter), the plugin project will be evaluated before
:app.

Since :app applies the Flutter Gradle plugin, which tries to
modify the dependencies of the plugin projects, we have a problem if the
plugin projects have already been evaluated. Adding
evaluationDependsOn(':app') to the plugin projects fixes this.

Updated example projects to the latest (plugin-enabled) Gradle build
files.

Also removed two unused imports in `pluginClass.java.tmpl`.

Ref: flutter/engine#3539

* Add start-up test for flutter_view sample

* add reportMetrics flag to startup test

* rewording in manifest.yaml

**THIS IS A BREAKING CHANGE.** See below for migration steps for
existing projects.

Previously, Flutter app code was built as a raw dylib on iOS.  Dynamic
libraries outside of a framework bundle are not supported on iOS, except
for the system Swift libraries provided by Xcode.

See:
https://developer.apple.com/library/content/technotes/tn2435/_index.html#//apple_ref/doc/uid/DTS40017543-CH1-TROUBLESHOOTING_BUNDLE_ERRORS-EMBEDDED__DYLIB_FILES

* Migrates Xcode build from app.dylib to App.framework
* Migrates flutter create template
* Migrates example projects

Migration steps for existing projects
=====================================

The following steps should be taken from the root of your Flutter
project:

1. Edit `ios/.gitignore`: add `/Flutter/App.framework` on a new line.
2. In the Xcode project navigator, remove `app.dylib` from the Flutter
   folder. Delete this file from the `ios/Flutter` directory in your project.
3. Run a build to generate `ios/Flutter/App.framework`. From the command
   line, run `flutter build ios`. If you have not configured app signing
   in Xcode, an alternative method is to open the simulator, then run
   `flutter run -d iP`.
4. In the Xcode project navigator, select the `Runner` project. In the
   project settings that are displayed in the main view, ensure that the
   `Runner` target is selected. You can verify this by exposing the
   sidebar using the [| ] icon in the upper-left corner of the main
   view.
5. Select the *General* tab in the project settings. Under the
   *Embedded Binaries* section, click '+' to add `App.framework`. In the
   sheet that drops down, click the *Add Other...* button. Navigate to
   the `ios/Flutter` directory and select `App.framework`. Click *Open*.
   In the sheet that drops down, select *Create folder references*, then
   click *Finish*.
6. In the project settings, verify that `App.framework` has been added to the
   *Embedded Binaries* and *Linked Frameworks and Libraries* lists.
7. In the Xcode project navigator, drag `App.framework` under the
   Flutter folder.
8. In the Xcode project navigator, select `Flutter` then from the
   *File* menu, select *Add Files to "Runner"...*. Navigate to the
   `ios/Flutter` directory, select `AppFrameworkInfo.plist` and click
   the *Add* button.
9. From the command line, in your project directory, run
   `flutter build clean`, then `flutter run`.

At this point your project should be fully migrated.

* Update iOS part of flutter_view to use the new platform message channel

* remove newline

* comments

* update Android part of flutter_view to use the new platform message channel.

* addressed comments

* addressed comments

* Add flutter_view sample

* Removed platform_services files

* Addressed comments

* update README.md

* Addressed comments.