feat(loaders): introduce loader cache

It useful if we disable cache for dynamic content, but want enable it for translation files (static content).
Also it useful if we need include translation into build file (cache in advance for production).

```js
app.run(function($translationCache) {
    $translationCache.put('/compiled/module1/locals/en.json', '{"MODULE1.HELLO":"Hi!"}');
    // Other translations string added by Grunt
});
```

feat(cache): introduce customizable loader cache

* `$translationCache` is fully flexible a string (name of an instance) or an instance itself
* `$translationCache` could be `true` for an AJS internal default

New feature usage:

```js
$translateProvider.useLoaderCache(false) // disable any cache (default behaviour)
$translateProvider.useLoaderCache(true) // use `$http({cache: true})
$translateProvider.useLoaderCache() // use our internal default `$translationCache` (actually `$translateProvider.useLoaderCache('$translationCache')`
$translateProvider.useLoaderCache('cacheService') // use the given identifying cacheService
$translateProvider.useLoaderCache(cacheService) // use the cacheService
```

This also introduces the feature loaders are provided with the option `$http` for additional standard params. Currently, only `$http.cache` could be defined.

Closes #529