Beta build 13

- Much better colours. (eg. no more grayish skin tones)
- Improved highlight recovery. (but still produces strange colours with a few images)
- Will now run without thumbnail updating if the FBO OpenGL extension isn't present instead of quiting.
- Fixed a potential crash bug with the Sony raw loading code.
- Busy cursor set while saving is in progress.
- Switching to another image extremely quickly during saving could result in a black saved image. Fixed.
- Default sharpening amount slightly lowered.