overlay: don't take cropping offset into account for overlays

This breaks 3d modes and serve very little use in the real world
renderers: rename stereo 3d mode flag to more distinct name
added: support SBS and TAB display of xbmc gui
dvdplayer: pass stereo_mode to renderers and select what to render
d3d: support anaglyph stereo rendering
gl: support anaglyph and interlaced stereo rendering
gl: support stereo rendering using opengl builtin system
dvdplayer: read stereo mode from filename same as omxplayer
add "3dmode" action to cycle between 3d modes