Wwise Unity Integration

The following breaking changes have been made to the AkCallbackManager.

• AkCallbackManager.AudioInterruptionCallback() has a new signature:
• AkCallbackManager.BGMCallback() has a new signature:
• AkCallbackManager.EventCallback() has a new signature:
• The callback classes are no longer nested within AkCallbackManager and have a hierarchy with many inheriting from AkCallbackInfo. Wherever possible, the associations and members of these classes mimic the syntax of their C++ counterparts.
• The gameObjID member of the callback classes is now of type ulong instead of IntPtr.
• The class AkCallbackManager.AkMidiEventCallbackInfo is now AkMIDIEventCallbackInfo. (Please note the capitalization of "MIDI".)
• The class AkCallbackManager.AkMusicSyncCallbackInfoBase has been removed. Use AkMusicSyncCallbackInfo instead.
• All of the members of AkCallbackManager.AkMusicSyncCallbackInfo.segmentInfo have been exposed as members of AkMusicSyncCallbackInfo.segmentInfo_*.