With --split argument, staging adi command can splits each package to
different adi staging project, the argument can work by 'osc staging adi
--split' or 'osc staging adi --move --split'. Note that, it will be
ignore --by-develproject argument too.
Update by_dp function in adi command, the old way is incompatible to
newer Leap development model, now we should try to check target package
in Factory as well, otherwise the submission from any other place than
Factory did not have 'devel' entry in _meta.
