Log Message:
Update archivers/lz4 to 131.

- New : Dos/DJGPP target, thanks to Louis Santillan
- Added : Example using lz4frame library, by Zbigniew Jedrzejewski-Szmek
- Changed: liblz4 : xxhash symbols are dynamically changed (namespace
  emulation) to avoid symbol conflict
- Changed: liblz4.a (static library) no longer compiled with -fPIC
  by default