* find all repo packages

* .dartignore

...by adding tests to our examples that don't import flutter_test, which
pins the relevant dependencies.

Also, provide more information when complaining about leaked transient
callbacks in tests.

Also, make tests display full information when they have an exception,
by bypassing the throttling we have for Android logging in tests.

Also, make the word wrapping not wrap stack traces if they happen to
be included in exception output.

Also, fix a leaked transient callback in the checkbox code.

* styles updates for the api docs

* update library docs

* use the new --favion and --use-categories options for dartdoc

* some docs cleanup

* update styles

* remove unused file

* document libs from sky_services

* scan directory of sky_services for libraries

* simplify error message when sky_services directory not found

* address review comments

Also, clean up a few interfaces that looked awkward when writing docs.

Previously, the client of PopupMenuButton needed to build all the menu times

when building the PopupMenuButton. This can get expensive if, for example, each
item in a scrollable list has a popup menu associated with it.

Now the client passes a builder function to the PopupMenuButton that gets
invoked only when its time to show the menu items.

This patch adds dartdoc to LazyBlock. Also, this patch fixes the scrolling
physics of LazyBlock. Previously, we updated a running simulation only when the
change in scroll behavior changed the current scroll offset. Now we update
running simulations every time the behavior changes because the simulation
might depend on quantities other than the current scroll offset.

LazyBlock is going to replace ScrollableMixedWidgetList at some point.

LazyBlock is intended as a replacement for MixedViewport. Rather than

maintaining a table of all the observed child sizes (like

MixedViewport), LazyBlock works by dead reckoning the location of the

children based on the existing viewport. This approach makes it easier

to resize children because LazyBlock doesn't cache any additional

information that would need to be invalidated.



This patch contains a first draft of LazyBlock that works in a simple

usage scenario. Subsequent patches will replace

ScrollableMixedWidgetList with LazyBlock and port the existing

ScrollableMixedWidgetList tests over to LazyBlock.



Related to #3075

* add a dev/dartdoc.dart script to generate docs for the packages/ packages

* remove description

* rename readme

* change to using --include-external

* move docs to dev/docs

Fixes https://github.com/flutter/flutter/issues/2713

Turns out card_collection had all kinds of bugs.

Initial version of complex layout performance test

Adds some names for common FractionalOffset values.

Previously, border with '0' was ambiguous. Sometimes we treated it as
hairline borders, sometimes as "don't show the border", though even in
the latter case we did some graphics work sometimes. Now we have an
explicit BorderStyle.none flag to not draw the border efficiently.

These were using Offsets, but they're really FractionalOffsets.

Fixes #2318

Instead, require an AndroidManifest.xml and always build an APK.

Fixes #2517

* justifyContent -> mainAxisAlignment
* alignItems -> crossAxisAlignment
* FlexJustifyContent -> MainAxisAlignment
* FlexAlignItems -> CrossAxisAlignment

Fixes #231

Removes an LTR bias in DismissDirection.

Fixes #2562

* left -> leading (Removes an LTR bias)
* center -> title (Widget was actually centered)
* right -> actions (Removes an LTR bias, asymmetric with leading)

Fixes #2348

Fixes #2353

This patch renames StatelessComponent to StatelessWidget and
StatefulComponent to StatefulWidget.

Fixes #2308

Fixes #1382

Fixes #1278

And fix the zillion issues that uncovered.

This reverts commit f41b3411, reversing
changes made to e33d8d96.

This was a bad check-in due to my mangling uploading a new version of the branch from a different machine.

This reverts https://github.com/flutter/flutter/pull/2639 and will be replaced by https://github.com/flutter/flutter/pull/2640

And fix the zillion issues that uncovered.

Well, all the easy ones, anyway.

For some reason `// ignore:` isn't working for me so I've disabled
lints that need that. Also disabled those that require a ton of work
(which I'm doing, but not in this PR, to keep it reviewable).

This adds:
- avoid_init_to_null
- library_names
- package_api_docs
- package_names
- package_prefixed_library_names
- prefer_is_not_empty
- sort_constructors_first
- sort_unnamed_constructors_first
- unnecessary_getters_setters

Most of the remaining widget examples are actually manual tests. This patch
moves them into //dev/manual_tests. A couple are examples of using services,
which I've moved to //examples/layers/services. The remainder are out-dated and
are removed by this patch.

Now that we don't require the Dart SDK to be in your path, it's hard to run
./dev/update_packages.dart. Instead, you can now run `flutter update-packages`.

Fixes #1906

Also, make dev/update_packages.dart skip directories that have no
pubspec.yaml, since firebase/ doesn't have one.

Makes it more obvious where we are spending our time on Travis.

Also added travis caching for the global pub cache to
speed this up!  Modeled what dartdoc does:
https://github.com/dart-lang/dartdoc/blob/master/.travis.yml#L13

@Hixie