[serverctl] allow to sync multiple and all sources in source-sync command
Breaking change: by default source are not synced anymore if it is fresh
(regards to synchronization-interval). To get the previous behavior an option
--force is added.
Closes #13886467
usr/lib/python2*/*-packages/cubicweb/entities/
usr/lib/python2*/*-packages/cubicweb/ext/
usr/share/cubicweb/cubes/
usr/lib/python2*/*-packages/cubicweb/*.py