Patch for GROUP_TO_GROUP_RATE Tally

This patch includes a few fixes to ensure that using GROUP_TO_GROUP_RATE Tallies will not cause frequent crashes as it had prior.  This was done by explicitly keeping track of the number of bin edges independently of the number of bins.  Further, the GROUP_TO_GROUP_RATE Tally output was fixed and improved.  Lastly, a few memory-related bugs were fixed in the course of tracking these bugs down.