* Updated to ZDoom 4140:
- Fixed: If you hit a wall at the right moment you would some times come out of a teleporter with sliding velocity.
- Fixed incorrect -= operators in vectors.h.
- Add support for user variables on things in UDMF maps. If you include an actor's user variable in its UDMF thing definition, that user variable will be set to the desired value for that actor when the map is loaded.

git-svn-id: http://mancubus.net/svn/hosted/gzdoom/trunk@1528 b0f79afe-0144-0410-b225-9a4edf0717df