[backend] handle .tbz kiwi files
[api] fix and verify binary release item compare
[backend] support static links also for checksum files
[backend] fix tracker cache generation, add trackercacheversion

Ignore the old cache if the version does not match.
[api] render only matching products in binary search

but include version information now
[api] support binary search by product versions
[backend] allow projectsourceinfo on remote projects
[api] Override require_login in SourceController

The SourceController uses models that require a proper login even on GET.
One example is getting the sources of a package with osc if source access
is disabled.

Signed-off-by: Jan Blunck <jblunck@infradead.org>