video modes in menu now also set vid_pixelheight and vid_conwidth/vid_conheight

video modes in menu now also set vid_pixelheight and vid_conwidth/vid_conheight
improved video modes menu, it now has widescreen modes, refresh rate, and more information about the chosen mode
renamed vid_pixelaspect to vid_pixelheight and inverted its behavior (smaller value now means that a pixel is wider than it is tall)
eliminated r_refdef.fov* fields, redesigned to use frustum plane slopes (like glFrustum takes) and calculate fov from height*4/3 rather than width, so widescreen now automatically uses higher fov accordingly, but 4x3 modes are the same as they always were, this also required generating the frustum planes differently in the renderer
changed underwater view warping to use frustum scaling rather than angles, this makes it a little smoother

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@5855 d7cf8633-e32d-0410-b094-e92efae38249