TODO list:

 - move all constants to configure space.
   - default ports.
 - add option to bind to specific interfaces.
 - fix the need to sync to be able to use gslist.
 - error messages using syslog (depends on error()).
 - add memory sharing support (multi-threading?).
 - add anti-aliasing support (using the X render extension).
 - add endianness agnostic support.
   - make showttf endian agnostic.
 - add missing encodings.
 - add TTF apple encoding.
 - make LOGSLP a runtime parameter.
 - fix xfstt crashing X Server when used with some fonts.
 - fix X error when X_SetFontPath on fonts with white spaces (unreproducible).
 - fix xfs protocol compliance.
 - implement missing support, check the code and the spec:
   <https://developer.apple.com/fonts/TrueType-Reference-Manual/>

Documentation:
 - differences: xfstt vs xtt-fs.
 - that font database is placed in the cache dir.

Code cleanup:
 - search for XXX and correct.
 ? move all contrib references in src to THANKS file (code cleanup).

License:
 ? change license in sources at src/ to GPL, need consent of Herbert,
   Steven and all contributors/patch submitters...
