Add support for angular-1.4.x

[razvanz]

Update disabling functionality to work with or without ngDisabled
Update angular dependency to angular: ~1.4.0 in bower.json

Note that without ngDisabled browser standards are followed. Expressions should not be passed to the disabled attribute since disabling functionality can be dictated solely by it's presence, ignoring any value.

[cgarvis]

Why do you need to setup the angular dependency to 1.4? I'm pretty sure with this change we lose the ability to install with any angular version under 1.4.

[razvanz]

My fix is strictly targeted towards angular 1.4, since under angular 1.3 there was nothing to fix. I did this thinking that you are following angular's versioning and not care about backwards compatibility with a minor update, just as all (official ones) the angular modules do. Not the best approach, but at least is consistent within angular environment.

TL;DR This is for a 1.4 version compatible only with angular 1.4.