* Update packages.
* Add many more global analyses.
* Catch trailing spaces and trailing newlines in all text files.
Before we were only checking newly added files, but that means we
missed some.
* Port the trailing spaces logic to work on Windows too.
* Correct all the files with trailing spaces and newlines.
* Refactor some of the dev/bots logic into a utils.dart library.
Notably, the "exit" and "print" shims for testing are now usable
from test.dart, analyze.dart, and run_command.dart.
* Add an "exitWithError" function that prints the red lines and
then exits. This is the preferred way to exit from test.dart,
analyze.dart, and run_command.dart.
* More consistency in the output of analyze.dart.
* Refactor analyze.dart to use the _allFiles file enumerating logic
more widely.
* Add some double-checking logic to the _allFiles logic to catch
cases where changes to that logic end up catching fewer files
than expected (helps prevent future false positives).
* Add a check to prevent new binary files from being added to
the repository. Grandfather in the binaries that we've already
added.
* Update all the dependencies (needed because we now import crypto in
dev/bots/analyze.dart).
The test places an embedded Android view at the top left, and verifies
that motion events that get to FlutterView are equivalent to the
synthesized motion events that gets to the embedded view.
See the README.md for more high level details.
