Improve error reporting of 'audit-argument-checks' package

Instead of reporting "Did not check() all arguments during setLocation" I report something like "Some arguments (id, name, location) left unchecked during setLocation"

I convert the function to a string and run a regex on it. The regex has been lifted from the `argumentNames` function in the battle tested [Prototype.js](https://ajax.googleapis.com/ajax/libs/prototype/1.7.1.0/prototype.js). Since checks are only run on the server, the variable names are not uglified.