add test_results verb

@wjwwood @tfoote Please review.
I would draw exactly the opposite conclusion from the facts. I would prefer using a relative path (`curdir`) as much as possible over an absolute path (`getcwd`). Most Python functions are working fine with relative paths and do not require to be absolute in the first place.

For the default value of the command line argument it is actually crucial to use `curdir`. When using `getcwd` a potential symlink will already be resolved and the `PWD` approach can't be applied after the fact. Also displaying the default value in the help text makes much more sense with `curdir`.