WAV-PRG 1.21 is out

This new version of WAV-PRG fixes some bugs in PRG2WAV:
- the lengths of RIFF and DATA chunks in generated WAV files arew now correct
- a possible memory leak has been fixed
- a small bug when detecting P00 files has been fixed.

Projects for the future:
- write an open-source Windows version (the current Windows version is closed-source and written in Delphi, writing one based on the current C code for Linux and MS-DOS could be good)
- port the plug-in architecture on Linux, so loaders other than Turbo Tape 64 can be converted.

Anybody wants to help?