[backend] export product flavor as well
[api] even more correct eager loading
[backend] publish: support regexps for redirect, support redirect functions
[backend] handle .tbz kiwi files
[api] fix and verify binary release item compare
[backend] support static links also for checksum files
[backend] obs_admin source deletion should handle _service generated files; also now works with a specific package; added explicit --delete option to allow a dry-run which reports what will be done

Signed-off-by: David Greaves <david.greaves@jolla.com>