feat($ionicNavBarDelegate): showBar returns whether navbar is shown
feat($ionicNavBarDelegate): showBackButton returns whether bar is shown

Closes #1076

If the user for example switches tabs,
$ionicNavBarDelegate.getPreviousTitle() will return the title from the
navbar within the previous tab.  In this case, the back button will not
be shown.  To not use the previous title in a case like this, you can
now do:

```js
var shouldShowTitle = $ionicNavBarDelegate.showBackButton();
if (shouldShowTitle) {
  $scope.previousTitle = $ionicNavBarDelegate.getPreviousTitle();
}
```
refactor(ionList): make sure attributes sync with delegate
refactor(item): Adjust item padding variables, create item-avatar-right
fix(ionHeaderBar): make it align after elements properly load

Addresses #945.
fix(scroll): Allow scrolling when touchstart target is an input, #1078
refactor($ionicLoading,$ionicPopup): factor out common code, add tests

Also fixes $ionicLoading flickering on ios7 in beta.1.
refactor($ionicPopup): add close() to returned promise, change closing

BREAKING CHANGE: $ionicPopup.show()'s button onTap function has changed.

When using `$ionicPopup.show()`, previously a button's onTap function
would only result in closing the popup and resolving the promise if the
 `onTap(event)` function returned a truthy value.

Now, a button's onTap event will *always* close the popup and resolve
the popup's promise, no matter the return value, by default. The only
way to prevent the popup from closing is to call
`event.preventDefault()`.

Change your code from this:

```js
$ionicPopup.show({
  buttons: [{
    onTap: function(event) {
      if (!shouldClosePopup) {
        return false;
      }
    }
  }]
});
```

To this:

```js
$ionicPopup.show({
  buttons: [{
    onTap: function(event) {
      if (!shouldClosePopup) {
        event.preventDefault();
      }
    }
  }]
});
```
fix(header): Header input too long on Android 4.2, closes #1081
test($ionicLoading): re-add missing unit tests
refactor($ionicLoading): make sure .hide() always happens after .show()

Fixes #1085.  Thanks @graemefoster.
refactor($ionicLoading): opts: +template,+templateUrl, deprecate content
refactor($ionicLoading): cleanup deprecations
refactor($ionicLoading): keep old options.showBackdrop, but undocumented
fix(ionInfiniteScroll): work properly if past horizontal boundaries

Fixes #1073

ion-infinite-scroll will now fire a scroll event if the user scrolls
past the left boundaries (if they exist) or the top boundaries (if they
exists).  This means infinite scroll works for vertical, horizontal, or
vertical plus horizontal scrolling situations.
fix(ionInfiniteScroll): remove listener on $destroy
chore(build): fix update-angular script
style(ionRefresher): pulling-text, refreshing-text default to '&nbsp;'

Fixes #1052.
docs(ionNavBar): chiefly recommend 'nav-title-slide-ios7' animation
fix($ionicLoading): stop race condition with show and hide

Fixes #1100.