This fixes up existing docstrings to conform to PEP-8 and PEP-257 guidelines,

and adds all missing class and method docstrings in the reviewboard/admin/

directory.

Ran pep257 --ignore=D100,D203 (disables module docstrings and the blank line

before class docstring rules). The only remaining errors were with the way we

wrap our long testcase docstrings.