Fixes NavBar

Fixes NavBar not showing the right buttons and not updating his title
correctly.
Merge pull request #621 from uniring/fix-navbar

refactor(navBar): fix title not updating correctly
test(navBar): add tests for changing title, left/right buttons

Closes #622. Closes #623.
feat(angular): Update to Angular v1.2.13, closes #600
perf(animations): throttle calls to requestAnimationFrame

Closes #582
style(dom-trace): always console.debug() so is easier to filter out
refactor(navBar): do not animate if there is no navDirection
click/tap refactor
refactor(scrollView): remove test code
chore(angular): downgrade to angular 1.2.12
fix(ionicLoading): make showDelay default to 0 (was 2000)
remove unused css test
feat(button): Increase hit area size of a button
tap polyfill removeClickPrevent and label fixes
feat(ionic): prefix all directives with `ion-`

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>
```
remove two classNames in one call
Minimal classList polyfill added
fix jshint
change classList fallback for multiple args
Remove background-color from .pane, .view