Add verification to no flag content when 'countall'.
Issue #1795690 by Matthew Grasmick: fixing syntax to match changes in services api.
Issue #822906 by skyredwang: add flag.count function.
by Edxxu : Renamed flag and flag_access functions because they were conflicting with hooks called by the Flag module.
by Edxxu : now can support flag module 6.x-2.x.
by Edxxu : Change flag_service.info to fix a installation problem.
Porting over changes from the 7.x-3.x branch
Renamed flag and flag_access functions because they were conflicting with hooks called by the Flag module. Also reworked the access function a little more.
Refactored flag_service_flag_access() since is_flagged() isn't using it anymore
Moved check for flag existence out of the access check and made it return a proper error
