Merge branch feature/jorgen.lind/ccache_for_c_externals with refs/heads/master...

Merge branch feature/jorgen.lind/ccache_for_c_externals with refs/heads/master into refs/merge-requests/100/train
3 jobs for !100 with feature/jorgen.lind/ccache_for_c_externals into master in 3 minutes and 6 seconds (queued for 2 minutes)
merge train