AbstractLoader now has a `getCacheObject` method that returns the cache object from the StorageManager that matches the loader's cacheKey.
CollectionLoader now caches the count for a cache
CollectionLoader sets the cacheKey on the Collection's lastFetchOptions
Brainstem.Collection#getServerCount now returns the cache server count from the collection.
CollectionLoader updates the cache regardless of the cache loadOption
Add documentation on AbstractLoader#getCacheObject
Merge pull request #22 from mavenlink/caching_result_size

Caching result size