archivers/ancient: Add new port

ancient 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. For simple usage both a simple command line application as well as a
simple API to use the decompressors are provided. The compression algorithm is
automatically detected in most cases, however there are some corner cases where
it is not entirely reliable due to weaknesses in the old format used.