Adjust the build system, packaging etc. to split osmo-gbproxy into its
own git repository. Remove tests and configs that aren't related to
osmo-gbproxy.
Related: OS#4992
These either remain from openbsc.git or slipped in while applying recent
patches from openbsc.git and do not belong in osmo-sgsn.
Change-Id: Ie9dc7514c3850010d0e9b3ab716b4f4e8d83594f
This is the first step in creating this repository from the legacy openbsc.git.
Like all other Osmocom repositories, keep the autoconf and automake files in
the repository root. openbsc.git has been the sole exception, which ends now.
Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7