Old code dumped the efb, which was no-longer relevant since the
backend gained xfb support.
New code dumps the colour texture which is about to be rendered to
the screen so correctly reflects the bypassXFB option.
This adds xfb support to the videosoftware backend, which increases it's
accuracy and more imporantly, enables the usage of many homebrew apps
which write directly to the xfb on the videosoftware backend.
Conflicts:
Source/Core/VideoBackends/Software/SWRenderer.cpp
Source/Core/VideoBackends/Software/SWmain.cpp
