Mass rebuild and ppc64/ppc64le support

Hi, We need to have a mass rebuilt done in per the f26 schedule. https://fedoraproject.org/wiki/Releases/26/Schedule At this step, I'm waiting for the fedora mass rebuilt to be fully published in order to start the RPM Fusion one. As some packages are still waiting to be signed, and the repository needs to be in sync, I hope to start the RPM Fusion mass rebuilt by the end of the week. If everything goes well, we will branch at the same time as fedora to avoid any surprise (which should be done by the end of the month). We also have an opportunity to start building for ppc64/ppc64le as Fedora uses them in koji. The builders are in place, it's just a matter to enable them in koji. The armhfp builders are still there, so no issue. Unfortunately no aarch64 builders has been found yet. It can still be enabled at a later point. Of course, we will need to report and fix FTBFS. Help will be welcomed in this area. Also while branching, I will be wiring lot of stuff from the infra side. We might need to verify/adapt our tooling for the new branches (rfpkg, packagedb-cli, package groups, etc). Help welcomed here also. Thx for the help in this area. -- - Nicolas (kwizart)