Script updated to v1.3 - Larger cel images and transparent colour issues fixed

This Amiga IFF/ILBM Export Script has been updated today and includes the following new enhancements/bug fixes:

• Aseprite documents where the cel image size is larger than the sprite size are now exported correctly to IFF.
• Transparent colour index is now handled properly.  You can now draw your sprites using a transparent background if you wish. Those transparent pixels will be translated to the colour index that you've defined as your transparent colour (which you can see/alter in Aseprite by selecting the Sprite→Properties menu option.)

Thanks to @Darthchillash for bringing these issues to my attention.