added -Contents-, removed inline markup from section headings
Add git.current_branch.
Support branch matching in git.latest.
Enable PEP263 pylint plugin. Fixes #7294.
Fix all `E3` `pep8` issues.

 * E301: expected 1 blank line, found 0
 * E302: expected 2 blank lines, found 0
 * E303: too many blank lines (3)
 * E304: blank lines found after function decorator
Fix `pep8` `E251` issues.
Fix `pep8` `E271` issues.
Fix `pep8` `E201,E202` issues.
Fix `pep8` `E231` issues.
Fix `pep8` `E211` issues.
Fix `pep8` `E203` issues.
Fix `pep8` `E711,E712` comparison to `None`, `True` and `False` issues.
Fix `pep8` `E226,E227` missing whitespace around bitwise, shift or arithmetic operator issues.
Fix `pep8` `E261,E262` issues.
Fix `pep8` `E502`, redundant backslash between brackets issues.
Fix `pep8` `E222` issues.
Fix `pep8` `E272` issues.
Fix `pep8` `W391`, blank line at end of file warning.
Fix `pep8` `E261` issues.
Fix `pep8` `E712` issues.