Refactor: Clean up unused code and comments
Refactor: Use more generic variable names

We'll eventually want to reuse this code for projects, texts,
and so on -- so we'll want generic names like "record" instead
of "user".
Made Enter keypress work on userdata form

Got the idea from http://stackoverflow.com/q/15417125/
Refactor: Use more generic function names

Apart from the names of the templates, almost nothing is
left that hardcodes the name "user". Now the controller can
be copied and that single "recordType: 'user'" line changed,
and the controller is ready to be used for other record types.

Better yet would be to turn this into a factory function, but
I'm not yet sure how that would fit with Angular. We'll leave
it like this for now.
Refactor: Make controller entirely generic

Now we can create more controllers for other tables without
duplicating any code.
Refactor: Add explicit dependencies to controller

If we want to minify our code later on, we'll want to specify
dependencies explicitly when we call our controller function.
So let's get in that habit right from the start.
Refactor: cosmetic changes

This should make controllers.js look slightly more internally
consistent once we've added a few more controller functions.
Refactor: Rename AdminCtrl to UserCtrl

At some point we may want an AdminCtrl that will inherit (or
maybe require) all the other single-table controllers: UserCtrl,
ProjectCtrl, TextCtrl... Besides, this controller is specific to
the users table, so its name should reflect that.
Focus correct input box when Add or Save clicked

This will allow users entering multiple records at once to keep
typing without interruption, and the Tab and Enter keys will do
exactly what they expect.
Give credit where credit is due
Improve UI experience of user CRUD form

Now the edit button changes its name in a context-dependant
way, and the whole form appears when it's needed and disappears
when it isn't. This ensures that the user always knows where to
type next.