CI infrastructure changes

Hi, the CI infrastructure exists because I found it import to have all Osmocom software compile and I set-up the Jenkins on my personal infrastructure. Since the adoption of gerrit having a stable build infrastructure is crucial though and my set-up was too flawed. In the past the VirtualBox running the Linux node got stuck and needed manual intervention. As it was running on my private system I was the only one capable of doing that. Sysmocom has offered to rent a dedicated build system and I have used some of my freelancing time to do the migration. * The Jenkins UI/Server jail has been migrated to the system that runs most of the other Osmocom infrastructure. DNS should be updated soon and then TLS will be enabled for the login. * OsmocomBuild1 is a Debian8.0/amd64 build slave with plenty of RAM and running on a SSD. All Linux builds should have been migrated away from the Ubuntu-1504-64 system to it. * rtl-sdr has some funny issue with make uninstall and Doxygen. If someone wants to fix it please go ahead, otherwise I will probably disable doxygen for this build. * I tried to have OpenBSC/OpenBSC-gerrit run in docker[1] so we can run all configurations at the same time but Jenkins is stepping on itself (and removing files from one label and impacting the other). At least we seem to have a benefit if two people upload changes at the same time. kind regards holger [1] I would prefer something without a server (as aborting a build doesn't abort the container) but still convenient enough to just create a new network namespace and remove it on exit [2] We are only executing the four configurations in parallel as the "build concurrently" option is stepping on each other (files vanish, etc).