Merge pull request #3326 from jedwards4b/archive_extensions

Archive extensions
Extend archiving support to accept a regex pattern as well as a cesm style file extension. This is
intended to allow any format for history and restart file names. Deserves a careful review.

Edit from Bill Sacks: A model can define both extensions and regexes, but probably shouldn't (i.e., should probably just define one style or the other).

Test suite: scripts_regression_tests.py (complete - all tests pass)
Test baseline:
Test namelist changes:
Test status: bit for bit

Fixes

User interface changes?:

Update gh-pages html (Y/N)?:

Code review: