use GL_RGBA storage for VDP_RGBA_FORMAT_A8
+ reverse_output_surface_render_rotate
use color parameter in softVdpBitmapSurfaceCreate
traceVdpOutputSurfaceRender{Output|Bitmap}Surface: print colors and flags
fix last color in renderbitmapsurface and add similar code to renderoutputsurface
use alpha too in render{}surface
rename tst/ dir to tests/
add tests harness (cmake/ctest)