Added Bitmap::save now supports float RGBA bitmaps.
Added Bitmap::save now supports float RGBA bitmaps.

svn path=/trunk/libavg/; revision=3471

scotty007/libavg,yyd01245/libavg,libavg/libavg,libavg/libavg,yyd01245/libavg,hoodie/libavg,th3infinity/libavg,libavg/libavg,th3infinity/libavg,scotty007/libavg,th3infinity/libavg,th3infinity/libavg,hoodie/libavg,libavg/libavg,yyd01245/libavg,hoodie/libavg,hoodie/libavg,scotty007/libavg,yyd01245/libavg,scotty007/libavg