refs #2: adds ability to read a .mxunit-watch file for configuration, al...

This adds the ability to read a .mxunit-watch file in the watch directory which is a JSON file that holds the host, list and debug options.  You can also specify a --save option which will write your host, list and debug options out to a .mxunit-watch file in the watch directory.

Tried to follow your coding style as much as possible, if I missed anything let me know and I'll update it to match.  Let me know what you think.