Locking mechanism cleanup

I'm thinking we could probably remove some of the locking mechanisms  
like Futex Locks and TSRM locks to tidy up the code a bit.  Let me  
know if you have any objections/thoughts on this, otherwise I'll  
clean house on a couple of these.

I haven't heard of anyone using SEM locks, but it seems like we  
should keep those for compatibility reasons (?), any thoughts?

-shire