[FASTFAT_NEW]

- Implement asynchronous and delayed close operations.
- Fix a logical bug in FatiClose code, which led to always closing the file object (and freeing respective FCB/VCB/CCB), and then checking flags and queuing a delayed close. Instead, it should only try to close if it's not marked as a delayed close.
- Support stuff added (queues, mutex for closing lists, etc).
- Misc cleanup, debug silencing.

svn path=/trunk/; revision=48525