Adds new '$ionicBind' service, which takes an object containing
binding definitions (similar to angular directive isolate scope
definition). Allows binding of any directive attribute & expressions
from a scope, letting us do normal attribute -> scope binding
without having to create isolate scopes.
Closes#555. Closes#669
BREAKING CHANGE: All directives are now prefixed with `ion-`.
For any directive you use, add the ionic prefix.
For example, change this HTML:
```html
<tabs>
<tab title="home" href="/tab/home">
<content>Hello!</content>
</tab>
</tabs>
```
To this HTML:
```
<ion-tabs>
<ion-tab title="home" href="/tab/home">
<ion-content>Hello!</ion-content>
</ion-tab>
</ion-tabs>
```
Starting a couple of versions ago, animations in navbar stopped working.
I took this as a chance to fix this, and ddo a refactor to make the code
more modular and testable.
Lots of manual dom manipulation was offloaded to angular directives, and
now we will not have bugs with end-user using interpolated class
attribute on their own nav-bar and overriding our own manually added
classes.
Fixes#521. Reordering now uses webkitTransform instead of
element.style.left. Additionally, as you drag the drag-element to the
top or bottom of the scroll-area, it will scroll it up or down as
allowed.
Refactors necessary: Common code from `<content>` and `<scroll>` moved
into js/ext/angular/controllers/ionicScrollController. Then `<content>`
and `<scroll>` expose the controller, and `<list>` can require it.
`<list>` then uses the controller (if exists) to pass the scrollView and
scrollEl to ReorderDrag, and ReorderDrag uses that to scroll.
Additionally, js/ext/angular/test/controller/ionicScrollController tests
much functionality that was untested before.
`content` directive stores scroll in view page history.
The history is passed down through $viewContentLoaded event, which is
broadcasted by navView directive when it loads a page.
