Add support for advanced queries ($sort, $in, $or, etc...)

This PR allows to use advanced queries with dpd-angular-cache.
A method isComplexQuery will determine if the query has an object in it and if so, will pass the JSON as query string (as mentioned on [this page](http://docs.deployd.com/docs/collections/reference/querying-collections.md#s-Advanced%20Queries-2035) instead of a params object in the $http get request.