Really fix issues with spaces in folder names

This PR revisits #118 which didn't actually fix the original problem because it used unescaped double quotes within a double-quoted string. This also makes sure the string doesn't get interpreted as multiple arguments.

I'm not really sure what the proper etiquette/best practice is for something like this (with regard to fixing a closed PR) so I apologize if this would have been better suited as a comment on the original PR.