Updated `diff-cover` to version 0.1.2, which fixes a bug
in which missing lines were over-reported
Rearrange pylintrc a little bit.
Tell pylint to shut up about us telling it to shut up.
Remove unused imports from common, as reported by pylint.
Fix strings that should be raw.
Remove unused imports from lms, as detected by pylint.
Remove unused imports from cms, as detected by pylint.