Fix floating label not appearing when subclassed

### The main thing

Internally, NineOldAndroids needs to find the setter/getter for the field specified in `ObjectAnimator.ofFloat(…)`. These setters and getters have to be public in order to [find them](https://github.com/JakeWharton/NineOldAndroids/blob/master/library/src/com/nineoldandroids/animation/PropertyValuesHolder.java#L412-L437) when the class calling it is subclassed. Since they weren't before, this caused subclasses of `MaterialEditText` to not animate the floating label due to the following error:

    E/PropertyValuesHolder﹕ Couldn't find setter/getter for property floatingLabelFraction with value type float

Setting them to `protected` apparently is not enough, nor is package level. It actually seems strange to me that it works at all in even a non-subclassed state, but I haven't dug into NineOldAndroids' code that much.

### Other stuff

I also made a tweak to `.gitignore` to ignore `.iml` files, since they're not intended to be checked into version control.

Last thing is removing the `applicationId` line from the library's `android` config, as this will actually cause the library build to fail starting in Android Gradle Plugin 1.0 (it's already in [RC-1](http://tools.android.com/tech-docs/new-build-system))

Please let me know if there's anything else I need to do. We would love to use this in our product ([Flipboard](https://play.google.com/store/apps/details?id=flipboard.app&hl=en)), but we need to be able to subclass it due to other under-the-hood requirements for our EditText fields.