Added 'options.debug' functionality and test file.

Wanted to enable protractor debug state as described [in the Protractor docs](https://github.com/angular/protractor/blob/master/docs/debugging.md).

Desired command: `protractor debug [config-file.js]`

This PR makes it available via: `options.debug = [Boolean] Default value: false`. 

I added ./test/debugTest.js and a new test task to Gruntfile. This will launch the debugger. You'll need to enter `c` <enter> a few times to progress through a few breakpoints, but there's a jasmine test that should eventually validate the debugger was successfully loaded. And then when done pretty control-c 2x to exit the debugger to continue test tasks.

Also, there's current a small parse error in the default protractor referenceConf.js that may give you an error when running debug mode first time. Need to manually fix that until they patch it upstream. https://github.com/angular/protractor/pull/179