Adding basic directory support.  Only really works for find if git_entire_tree=true.
Adding candidate_fn caching.
Fixing user regex test now that we're guessing input directories.
Fixing relative paths within git directories.
Force the input string to have a trailing slash if want to consider the whole thing a directory.
Update README to reflect new config.
Merge pull request #22 from mattspitz/add_dirs

Add support for directories!