Replacing the google apputils with docopt.

Breaking the grow CLI into separate, dedicated files to make it easier to update and read.
Fixing the WSGI app to no longer use gflags.

Added a --debug flag to the run command that runs the server in debug mode.
Merge branch 'master' of github.com:grow/pygrow into feature-docopt

Conflicts:
	bin/grow
	grow/commands.py
	grow/common/utils.py
	grow/server/manager.py
	requirements.txt
Pulling back to the upstream master version.

Accidentally merged the wrong part of the conflict.
Moving the `multiprocessing` to the sub commands to fix hanging commands.
Merge branch 'develop' of github.com:grow/pygrow into feature-docopt

Conflicts:
	grow/commands.py
Bringing back the pygments requirement.

Accidentally removed in a merge.
Minor bugfixes.
Merge branch 'develop' of https://github.com/grow/pygrow into develop