utility functions for SID players

 This library contains various things deemed useful to all SID players
 (Emulations of the C64's SID chip (MOS 6581) and CPU (6510)), and
 currently every player seems to be re-inventing. It is used by
 several "player" applications, e.g. sidplay.
 .
 Support so far is:
 .
  * INI file reader.
  * MD5 key creation.
  * Song length database parser.
  * Sid filter file parser.
 .
 Coming soon:
 .
  * Playlist parser (load and save).
  * STIL parser.