* 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
This changes the DocSetPlatformFamily key to be "dartlang" instead of the name of the package (usually "flutter"). This is so that the IntelliJ plugin for Dash will be able to go directly to the docs for a symbol from a keystroke, instead of needing to search all the docsets each time.
Without this, flutter isn't part of the list of package names it searches. After this, it finds the flutter docs because they're declared to be part of the "dartlang" family of docs.
Dashing doesn't have a way to configure this, so we modify the Info.plist directly to make the change.
