Added support for Radar Search service

Hi, 

I just added support for Radar Search Service.  It allows you to search for up to 200 Places at once, but with less detail than is typically returned from a Text Search or Nearby Search request.
I needed it for some work I was doing and I wanted to share it with you.
I tried to follow the existing style and pattern. 
It's working. 
Let me know if you have any questions!

Cheers,
Serge