import cmdloop from pythons cmd.py before modification
modify cmdloop to no longer treat return value as stop flag

instead, treat the return value as success/failure and require
self._stopping to be set to True to stop the loop.
fix locking

the lock_required decorator needs to actually return the result of the
function
make broctl use a modified version of the Cmd class

The modified version of the cmd class doesn't use the turn value of
commands as 'stop' but instead as 'success'.  This way command functions
can directly return success/failure as True/False