The sidplay port needs to be updated to a current version, because
the old distfile vanished.
The feature changes are minor:
- Merge sidplay option -t patch.
- Fix big-endian bug in sid2wav. (Axel Wefers)
- Include <string.h> for compatibility with libsidplay-1.36.51
compiled with old non-standard <strstream.h>.
Thanks to 'Tilman Linneweh' for reminding me.