Ensure PantherIDs are validated for input

[sergiopantoja]

When adding a new ARCH project, Allen knew the student's name, but not her Panther ID. So he put "N/A" in that field. The form was validated and a new project was created.

First: ensure that our controller checks the Panther ID input (needs to be 7 digits, a string of numbers, etc.). Maybe even create a reusable ValidateService to inject into all controllers w/ forms.

Second: I'm sure there were errors thrown out into the Javascript console (e.g. Firebase won't create a new user location named "N/A" because it's not numeric), but this should have resulted in a visible error.

We can use deferred promises and Firebase's built-in error callbacks to check if a write was totally successful or not, and then use those callbacks to display a message to the user. Look for similar code in the soon-to-be-committed CommentService.js file.