[WIP][1.0][CacheResolver] Resolver get rid of get browser path

This PR is attemp to address @LouTerrailloune [commen](https://github.com/liip/LiipImagineBundle/pull/282#issuecomment-30304575).

It based on thttps://github.com/liip/LiipImagineBundle/pull/282 PR so please consider reviewing and merging that one first. 

To say briefly about changes:

* [ResolverInterface] The `resolve` method can return NULL which means we dont have a cache yet and a string. String is an url where the image located.
* [ResolverInterface] The method `getBrowserPath` was removed.
* [CacheManager] The method `getBrowserPath` now use resolve method to find a cached image url. If it fails it generates an url of filter action.
* Removed dependency on cache manager almost in all resolver. WebPathResolver still needed it