This class translates an NSPredicate query into to an appropriate mongodb query encapsulated within an NSDictionary.
The resulting NSDictionary may then be serialised (Using NSJSONSerialization for example) into a JSON format to be interpreted by mongodb.
Use cases: Makes it very easy to construct queries to send to mongodb based backend platforms such as Deployd
##Supported query types: ###logical
- $not
 - $and
 - $or
 
###comparison
- $lt
 - $lte
 - $gt
 - $gte
 - $ne
 - $regex
 
###membership
- $in
 - $geoWithin
 
###javascript
- $where