Support for MSX image formats

[GoogleCodeExporter]

The MSX home-computer used some standarized graphic file formats:

1) MSX-BASIC Graphic format.
- Extensions: GRP, SCx (x = screen mode used: SC2,SC5,SC6,SC7,SC8,SCC)
- Palette data included on the file for screens 5-7, optional on SC2.
- Simple header:
   ID Byte: FEh
   Word: START. Address on VRAM to start loading
   Word: SIZE. Picture size in bytes
   Word: 0000h
   <raw data on the respective SCREEN format, as described by the V9938 & V9958 datasheets)>


2) Graph-Saurus format:
- Extensions: SR5, SR7, SR8, SRS. External palette set with extension PLx. SRS 
& PLS = screen-12
- May be raw or compressed. Raw format is identical to the MSX-Basic format, 
but the palette isn't included on the file. The compressed file needs some 
reverse engineering, but it's said to be a simple runlenght encoding.

3) G9B format:

The specs for this format and sample files can be found here:
http://www.teambomba.net/gfx9klib.html


If this request gets approved, I'll select and attach some (1) and (2) sample 
files.

Original issue reported on code.google.com by [email protected] on 4 Oct 2012 at 2:25