Send the right RefMsg, please...

So this is interesting. If you disable Planar Reflections and visit an age with a DCM, you will crash after a few minutes. This is because plDynamicCamMap is sending the wrong plRefMsg to the plLayer. This does nothing (aside from waste time), so we keep sending the ref again and again and again and again until we get some weird heap corruption and KABLOOOOOOOOOOOEY!
Merge pull request #369 from Hoikas/dcm

Dyanmic Cam Map stuff