This patches introduces a new script manager and move the
functionalities of create_sqlite_db, start_freshmaker_from_here and
start_frontend_from_here to this new script.

During development, we need to set PYTHONPATH and
FRESHMAKER_DEVELOPER_ENV to run commands from freshmaker/manage.py,
the removed scripts only sets those two variables for limited commands,
not all. New script manager fixes this. That is useful for me
particularly to run commands related to database migrations as an
example.

Script manager accepts argument either help, -h, or --help to print
usage. Command createdb maps to create_sqlite_db, runfrontend
maps to start_frontend_from_here, and runfreshmaker maps to
start_freshmaker_from_here. In addition, all commands
freshmaker/manage.py accepts are usable as well, for example manager db revision --help.

Signed-off-by: Chenxiong Qi cqi@redhat.com