* unnecessary escapes fixes

* replace some strings with raw strings

* update regexp

* address review comments

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

* add trailing commas on list/map/parameters

* add trailing commas on Invocation with nb of arg>1

* add commas for widget containing widgets

* add trailing commas if instantiation contains trailing comma

* revert bad change

* [Gallery] Fortnightly demo moved from flutter/samples.

* [Gallery] Fortnightly analysis corrections.

* [Gallery] Minor rename.

* [Gallery] Making floats ints.

* [Gallery] Fortnightly minor visual polish.

* [Gallery] Formatting.

* [Gallery] Upping package version for gallery to support fortnightly demo.

* [Gallery] Fortnightly copy correction.

* [Gallery] Fortnightly study polish.

* [Gallery] Fortnightly polish.

* [Gallery] Fortnightly copy correction.

* [Gallery] Fortnightly copy now held in '''.

* [Gallery] Fortnightly comment.

* [Gallery] Updates necessary when flutter_gallery_assets updates.

* [Gallery] Updating macrobenchmarks because we updated flutter_gallery_assets.

* [Gallery] Moving spaces to beginning of copy lines.

* [Gallery] Copy correction.

* [Gallery] Adding tooltip to satisfy smoke test.

* [Gallery] Minor pr feedback.

* [Gallery] Forced upgrade.