[repo_cache] Skip repos that are not available
Update main to new service model

Also remove log_downloader from it and add resolver
Pickle skipped repos to reduce startup time
Use rpmlib to get srpm metadata
Use epoch 0 insted of None for hawkey queries

hawkey doesn't like null epochs
Show dependency changes instead of buidroot diff

Dependency changes should now be more accurate because they are repo aware.
That makes buildroot diffs redundant.
Remove log_downloader entirely
Modify only complete builds in migration
Implement polling for new repos
Reuse build group for processed builds
Fix scheduler using anonymous session
Reallow using id in group URL

People might already have bookmarked it, let's keep backwards compatibility for
them
Limit dependency change count to 10 in package overview
Also restart httpd when deploying
Update production config
Update polling test
Don't call build_registered for real builds

Dependency resolution will now happen automatically in resolver due to
deps_processed flag being set to false
Save srpms from get_latest_srpms to cache
Display dependency changes since last build