rose.config_tree: configuration import library.
Merge branch 'master' into config_tree
rose.c3: get_base_names now supports optional args.

rose.config_tree: no longer require a nested function.
rose.c3 and rose.config_tree: class for self tests.
Merge pull request #624 from matthewrmshin/config_tree

rose.config_tree: configuration import library.