Handle endian conversions from the Timidity process

Handle endian conversions from the Timidity process
There's no guarantee that Timidity will write raw samples with the same byte
order as the receiving process, such as if one is run under a CPU emulator and
the other is not. Worse, it only has an option to swap bytes instead of forcing
a specific order.

To get around this, make Timidity output a RIFF WAVE byte sequence, which will
guarantee little-endian ordering. If both Timidity and the receiving process
are big endian, this can cause a conversion on both ends.