- allow the GUS to change sound fonts at run time.
- implemented sound font manager support in the GUS synth. This works but also made me realize that the SF2 support of this synth has been rather broken, apparently forever.
- added the missing handler for reading Timidity configs from the lump directory.
- fixed incomplete init of the GUS synth when no soundfont can be located.
- fixed bad initialization of WildMidi sampling frequency. It would default to 11.025 kHz if no valid rate was set. Now it will use the sound device's native frequency.
