SpecRunner, editor support, and readme tweaks

 * Renamed root to `uproxy-lib-root` so it's easier to tell projects apart in sublime (when you have windows multiple open)  
 * Tweak to README to explain how to generate the common-grunt-rules JS
 * Fixes https://github.com/uProxy/uproxy/issues/474 (SpecRunner naming so Chrome apps don't get broken)

TESTED: 
 * grunt test
+1 to this but should we consider not keeping the runner too? (next line)