This centralizes all config options into config.py,
eliminating a race condition where not all config options
from modules may have been registered by the time the
config file is parsed. Plugins are now provided a
separate config object, to which they can add their
own individual options before parsing the config file themselves.
Change-Id: I737bfe092ff71a1275f27de5b9328e9d23032a24
Closes-Bug: #1459448
5687cd9b93