This is the second try at 5326c36a5f. The difference here is that we
have moved GL_CONTEXT_MGR into kicommon first which will hopefully
address some of the Windows linkage issues
The GL context lock needs to be shared across kifaces. Otherwise, we
can end up blocking the lock from one kiface. Unfortunately, I can't
find the issue in GitLab right now for where the footprint viewer shows
a blank screen after opening too many contexts. But that's what this
fixes.
09e30adbb1