Add code to translate flagfiles into .ini config files so that we can
deprecate and, eventually remove, --flagfile.
By using the flagfile compat code, we no longer need to process the
contents of flagfiles as CLI options and we can reduce the number
of CLI options to a sane set:
--verbose
--logdir
--logfile
--use_syslog
--use_stderr
--connection_type
--sql_connection
--api_paste_config
--state_path
--lock_path
--fake_network
--fake_rabbit
This, in turn, means we can remove the evil hacks which we needed in
order to register CLI options after the initial parsing of the command
line.
Change-Id: I9e24008fa634d7c8378b253c1f7a6d2169076086
393e28bd3d