pep8 fixes
Add the poc argument to the get_packager_acls method in the pkgdb2 module

The poc arguments allows to filter the ACLs retrieved based on the point of contact of the
packages.
If poc is None (default), then all ACLs of the packager are retrieved.
If poc is True, then only the ACLs of the packager for the packages on which he/she is
point of contact are retrieved.
If poc is False, then only the ACLs of the packager for the packages on which he/she is not
point of contact are retrieved.
Add tests for the poc and count argument of get_packager_acls

Adjust the other tests as well.