Some trivial patches to add a few more worldfile extensions and make documentation consistent :
- JPEG : Add support for '.jpw' and '.jpegw'. Documentation didn't mention '.jpgw' which was supported. Updated with '.jpw' and '.jpegw'
- BMP : Add support for '.bpw'. Documentation didn't mention support for worlfile. Fixed
- GIF : Add support for '.gifw'. Documentation didn't mention '.gfw' which was supported. Updated, and with '.gifw' also.
- PNG. This one is a bit weird. Code and documentation mention tfw and tifw ?? Patch to replace them with '.pgw' and '.pngw'
- TIF. Add support for '.tiffw'. Documention didn't mention '.tifw' which was supported, but '.tiffw' which wasn't... Updated.
That's all !