MIDI Connectivity

[michelkeijzers]

Add MIDI support for direct connection, so that MIDI can be used to transfer sounds directly, instead of loading/saving PCG files or using external utilities like MIDIOX.

Rationale: Easier workflow, adding audition and editor features becomes interesting because the transfer workflow is easier/faster.

Open Issues: For some workstations MIDI is probably too slow (Kronos), also testing will be very time consuming.