CURATOR-84 More flexibility for InterProcessMutex extensions

Credit goes to Jozef Vilcek for the initial patch. I just created a PR from the original patch he had created.
Yes, I was just about to comment back. The plan was for a client using the ```InterProcessMutex``` to specify their own ```LockInternalsDriver``` with different parameters than the one provided by the default ```StandardLockInternalsDriver```. We definitely need this to be public. 

I'm not sure what you mean by "Also LockInternalsDriver would need to be public?". Could you please elaborate?