Our "StatBag" statistics class was 1) 32 bit 2) heavily locked 3) still allowed for...

Our "StatBag" statistics class was 1) 32 bit 2) heavily locked 3) still allowed for lock-free operations for high speed counters.
This commit 1) makes the StatBag 64 bit on 64 bit systems, 2) removes all locks and 3) has gone AtomicCounter 'native'
The upshot of this is that 64 bit users will suddenly get 64 bit counters. A second upshot is that multicore systems should now see consistent statistics again.
One important thing that changed is that the StatBag class used to be completely thread safe, and now it no longer is. You can't declare new counters while the StatBag is in use. This should not be happening, but you never know.
Finally, there is now a StatBag unit test.