Simplified and Traditional Chinese translations for doc 22 unit testing
feat(directive): add possibility to mix translation interpolation with other text in element body

This adds possiblity to use like this:
```html
<span translate>Hello {{translation_id}}!</span>
```
Given that $scope.translation_id = "CHARACTER_NAME", which translates into "Muppet", this would become
```html
<span translate>Hello Muppet!</span>
```

Closes #461
fix($translate): return $missingTranslationHandler result when no translation was found

Instant translations do not return result of $missingTranslationHandler invocation.
fix(docs): Fix typo

$translaterPartialLoaderProvider was misspelled. It should be translatePartialLoaderProvider
fix(demo): fixes wrong method call in demo
fix(service): addition of preferred language to fallback language stack is now preventing duplication if already contained in the fallback stack
feat(service): preferredLanguage can now be set during runtime
fix(package.json): remove unnecessary relative paths from package.json
chore(): update to latest bower (invalid transient dependencies)
fix(storage): fix 'DOM Exception 18' at feature detection

This fixes a unhandled exception (i.e. iOS) when checking for local storage support.

fixes #629
fix(storage): fixup 75504cbe

Fix an eventual issue of browser which do not throw an exception.
fix(service): load fallback languages also for instant and filter
fix(directive): change event for listening to `$translateChangeEnd`

Under some circumstances, the cloak was not be removed:
* the translations are already stored (not via custom loader)
* no customer loader defined anyway

This changes the listening event to the change-end phase, which will be
invoked always.

Fixes #658
fix(directive): improve the cloak-directive's performance

This removes the listener immediately it was invoked the first time.
fix(translateService): prevent multiple XHR calls
fix(translateService): fixup/rewrite for b48f6bb (specs)
Update CONTRIBUTING.md
fix(docs): fix example in directive ngdoc-documentation (fixes #678)
Merge pull request #679 from tspaeth/canaryForApiDocFix

fix(docs): fix example in directive api-documentation (fixes #678)
fix(bower.json): Avoid 'invalid-meta angular-bootstrap-affix is missing "ignore" entry in bower.json' when installing via bower. As suggested here: bower/bower#1388
fix(service): add shim for indexOf and trim #638