Use set functions

Currently, the class BranchDescription has overloaded non-const and const functions with the same name.
This makes it difficult to find the non-const function calls that might change data members.  This pull request renames the overloaded non-const functions to something more descriptive, usually beginning with "set" or "insert".
NOTE:  This pull request does not affect DQM at all.  The marking of DQM as required was due to an extraneous file in the first push.  Unfortunately, correcting the push does not remove the obsolete signature requirement.