Grab a few random fixes like deleting old abstract-class-little-used,
abstract-class-not-used, and star-args.

Bug: None
Test: `./pylint *.py` shows no regressions
Change-Id: I494379e18da002d479cb193412fcc49f8c66f376
Reviewed-on: https://chromium-review.googlesource.com/1103763Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>