Adding support to 'within' query for nested fields

[rjburdish]

This resolves #25. When querying an object structured as the below, with nested location attributes, the query will fail. After this change, the structure below is now supported as long as the correct options are passed in.

{"stores": [{
  "name": "Bob's",
   "phoneNumber": 2345678987,
    "location": {
        "street": "Abbey rd",
        "city": "NY",
        "geodata": {
              "geopoint" : {
                   "longitude": 1234.45,
                   "latitude": 1234.45
               },
               "geohash": "dxguy2es3"
        }
    }
}]
}

[catrawalkar]

@rjburdish Hi, is there any problem in this pull request ? Why this is not merged in project yet?

@codediodeio

Facing the same problem for nested fields. Please merge :)

[tarounen]

Hello, can this be merged please ? I'm facing the same issue @codediodeio

[IgoPeg]

@rjburdish your changes contains a conflict. Could you please resolve the conflict?

@codediodeio Would you please review the changes - these feature would be very nice.

[BlackRider97]

Is there any issue with PR apart from current merge conflicts ? I think it will be a good feature to support geo-point under nested object. Adding an example in readme will be also helpful