(svn r10121) -Codechange: split renderer from rest of code; no longer any code directly accesses the video-buffer

-Add: added NULL blitter and renderer, which are always used for -vnull
-Add: dedicated driver doesn't blit nor render by default. Can be overruled by user. (-D -b 8bpp-optimized)
-Remove: removed CTRL+D from win32, which is incompatible with above
-Add: extended screenshot support for PNG and BMP
-Codechange: remove all hardcoded 8bpp references and replace them with more dynamic ones
-Codechange: minor stuff in blitters

source.list

@@ -297,6 +297,8 @@ blitter/8bpp_optimized.cpp
 blitter/8bpp_optimized.hpp
 blitter/8bpp_simple.cpp
 blitter/8bpp_simple.hpp
+blitter/null.cpp
+blitter/null.hpp
 blitter/blitter.hpp
 
 # Sprite loaders
@@ -304,6 +306,13 @@ spriteloader/grf.cpp
 spriteloader/grf.hpp
 spriteloader/spriteloader.hpp
 
+# Renderer
+renderer/8bpp.cpp
+renderer/8bpp.hpp
+renderer/null.cpp
+renderer/null.hpp
+renderer/renderer.hpp
+
 # NewGRF
 newgrf.cpp
 newgrf_canal.cpp