Remove unnecessary ref temp insertion.
Factor changeRetToArgAndClone().

Further factoring of changeRetToArgAndClone() to get the main routine down to less than a
page.  Also, removed insertions of reference temps which are unnecessary due to the
insertReferenceTemps mini-pass that occurs at the end of callDestructors.
Remove another ref temp insertion.
Correct verification problem in 60 test cases.

Removal of the code that inserts ret_to_arg_ref_tmp_ was incorrect.  The code is inserted
when FLAG_REF is absent, not present.

Removed the ancient (and apparently not very accurate) test for premature frees.
Update comments per Lydia's suggestions.
Merge branch 'master' into factorCRTAAC
Merge branch 'factorCRTAAC' of github.com:hildeth/chapel into factorCRTAAC
Merge pull request #744 from hildeth/factorCRTAAC

Factor changeRetToArgAndClone().

Remove insertion of reference temps done later in insertReferenceTemps().