[backend] proto projects are not enough data for remote aggregates
[backend] fix macro block handling
[api] extend check for supereseded_by settings to avoid to be set to zero
[api] fix ruby syntax
[backend] add ppc64p7 architecture
[api] add ppc64p7 architecture
[api] add ppc64p7 to xml schema file
[api] fix storage of download on demand data in api partially
[api] add test case for adding, editing and removing DoD definitions and complete last fix
[backend] document the BSConfig:sibling* and partition settings
[testsuite] add some basic checks for generated repomd data.

This will allow us to include createrepo into our testing to avoid broken repositories
in future. We need to hard require the tested version of it then in the obs-server package.
[backend] also restore the signkey when undeleting a project
[webui] set expire date for avatar icons
[webui] disable miniprofiler by default - it disables caching
[webui] replace more images with sprites