replaced all references to vid.conwidth and vid.conheight with vid_conwidth.integer...

replaced all references to vid.conwidth and vid.conheight with vid_conwidth.integer and vid_conheight.integer
replaced all references to vid.realx/vid.realy with 0
replaced all references to vid.realwidth and vid.realheight with vid.width and vid.height
replaced current_vid_* variables with vid. fields (vid.width, vid.height, vid.bitsperpixel, vid.fullscreen)
vid_glx.c: replaced scr_width/height with vid.width/height
vid_wgl.c: replaced window_center_x/y with calculations as needed, and replaced window_width/height with vid.width/height, and some other minor cleanups
removed VID_GetWindowSize function

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@5284 d7cf8633-e32d-0410-b094-e92efae38249