Added a faster/integer version/overload for a special default_color_converter code path.
Replaced the pixel_format_type<> logic/machinery/typedefs with simpler gil::image<> typedefs.
Moved more shared logic from the gp_image class to the formatted_image(_base) class (dimensions_mismatch(), get_raw_data() ...).
Simplified the formatted_image_base::check_type_match<> functor.
Added ROI/offset view support.
Replaced the multiple template parameter formatted_image design with a single template parameter and a traits class (formatted_image_traits<>).
Added proper and/or missing formatted_image<> copy_to() and copy_to_image() member function overloads.
Moved the core 'generic' and 'in-place' transform logic into the base formatted_image<> class.
Updated the GDI+ implementation with the above changes.
Fixed the GDI+ implementation to include CMYK support only for GDI+ 1.1 builds.
Minor other refactoring and stylistic changes.
