The bulk of this commit is "code rape"--or rather, caressing, rewritten for readability.
Actual changes/fixes:
- fixed "walking" in 2d mode
- fixed DELETE key in OSD in SDL build
- main loop in general (timeout for event wait after 200 ms so that highlights blink)
- access to some pr_override* variables in m32script (suggested by Roma Loom)
- API cleanup (added statics and consts here and there)
git-svn-id: https://svn.eduke32.com/eduke32@1644 1a8010ca-5511-0410-912e-c29ae57300e0
