ugly but working hack to capture GL actors
added new display driver "stdout_sdl"
removed stale glx_driver.hpp include
fixed help message
fixed depth mashup
use -c24 argument again, switched to stdout_sdl driver (snapshotting GL and non-GL actors works now) \o/
some cleanups, flip GL captured buffer using a 2nd buffer + CPU
Merge branch 'master' of github-rigid:Libvisual/libvisual into lvtool-opengl-working
removed SDL_HWPALETTE flag, added list of available output drivers to help text
Merge branch 'lvtool-opengl-working', should close issue #44