Merge pull request #2362 from RosettaCommons/roccomoretti/rosettacm_template_length
Fix bad error message with RosettaCM length mismatch.
If you have a mismatch between the length of the template and the length of the input in RosettaCM
(Specifically if your templates are accidentally longer than your input.)
You can get really non-informative errors. (e.g. memory corruption due to writing off the end of a vector in release mode.)
Check for this condition, and pop up an intelligible error message if it occurs.