Ancient - Modern decompressor for old data compression formats

This is a collection of decompression routines for old formats popular
in the Amiga, Atari computers and some other systems from 80's and 90's
as well as some that are currently used which were used in a some
specific way in these old systems.

Decompression algorithms provided:
- bzip2
- Compact (Unix)
- Compress (Unix)
- CrunchMania by Thomas Schwarz
- Disk Masher System a.k.a. DMS
- File Imploder
- Freeze/Melt
- gzip
- Pack (Unix)
- PowerPacker
- Quasijarus Strong Compression
- Rob Northen compressors.
- Turbo Packer by Wolfgang Mayerle.
- MMCMP: Music Module Compressor
- SCO Compress LZH
- StoneCracker
- XPK-encapsulated files

This code should compile cleanly on most C++17 capable compilers, and it
is tested on clang and MSVC.