Add an option to use the HRTF time delay measured from the dataset
Fix header guard and remove duplicate code
Add a new ALsoundfont object type

Includes a basic hierarchy for presets, instruments, samples, zones,
generators, and modulators.
Make alIsSoundfontSOFT check soundfont IDs
Properly initialize and cleanup the soundfont map
Add methods to create and destroy presets
Move the soundfont and preset extension functions to separate sources
Rename some ALsoundfont fields
Call the right delete method when generating presets fails
Allow creating instrument objects
Fix compiling without FluidSynth
Add functions to set a soundfont's sample data