* 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).
