Allows better sharing when !Draw is also in ROM.
Fix long (long) standing bug of not being able to drag JPEGs into !Paint using the RAM transfer protocol - some dubious pointer arithmetic meant the wrong address of JPEG data was used and so gave an error.
The 3 paths that result in a JPEG->Sprite conversion now share code too.
Remove local definition of FileType_JPEG, use that in the exports.
Version 2.05. Tagged as 'Paint-2_05'