Fairly substantial code restructure.
- Removed soundQueue/soundQueueItem, replaced with NSMutableArray for simplicity.
- Cleaned up header/declarations to latest objective C standards
- Splitting out AudioPlayerUtilities into separate C file for cleaner including
- Removed redundancies with queue counter/arrays/isDone (count and completion are now entirely referenced from NSMutableArray soundQueue structure)
- Adding structure for later implementation of seeking to an offset