fimp portable C version by JOTD

Uses a 68000->C automatic translation using awk & a C runtime with a limited
instruction set, but enough to make the imploder algo run.

Notes:

- Extremely slow so I do not recommend modes higher that 0. I have tested a lot
with mode 0, but not   a lot with other modes, and there may remain bugs in the
68000 core although it has been checked extensively.
- outputs ATN! prefix. Change the source code to output IMP! prefix if you like
- compared to the Amiga version of fimp, 4 bytes are missing in the end. I don't
know what they're used for, they're
  certainly not used to unpack the data.
  
Contributors:

- imploder.s source code taken from Beermon sources
- used some emulation code from F.A.S.T (Atari ST emulator)