Handling space in paths / Reversing order or role_path selection

I think the commit [1b4eb84](https://github.com/ynk/ansible/commit/1b4eb84b696e47ab0c66ac1ca19e63dc7301b2b5) will be very handy for mac users as i am. Thing is, if you have a space in your `given` path, then python will output the path within single quotes, which results in a false state of the `if given.startswith("/"):` test.

The second [298f52a](https://github.com/ynk/ansible/commit/298f52a4f839b06630783b1fd07d0440e02858c2) looks more pratical to me. It looked like the `DEFAULT_ROLE_PATH` constant was added to the end of the `possible_paths` list, resulting in a default-first/configuration-last order, which i think should be reversed, as configuration should be prior to default.