Improve the AIL functionality support

[Wohlstand]

Continuation of the #134 issue.

To make libADLMIDI / libOPNMIDI being suitable to be used with games like SystemShock, it's need to extend the support to handle existing functionality of the AIL library:

• Allow parallel playing of different XMI tracks.
• Handle support for more of built-in XMI events.
• Add support for more events and hooks, and state checks if needed.

[Wohlstand]

@Interrupt, feel free to give any notes here if needed.