Cleanup
Removed block storage factory, stopped using the in-memory transaction locator
Parallel transaction validation implementation
Removed some unnecessary logging
Cleanup and making sure that block validation can't be skipped by exiting
Added logger for OpCheckSig
Removed logging from OpCheckSig
Using a fixed thread pool.  This design won't work without tweaks.  When we try to validate more transactions than there are threads in the pool it will hang.  The easiest fix is to change to a cached thread pool.
Using cached thread pool