Added mongo db version property to response.
Added mongo db version property to response.

Mongo DB adds a version field to every document.  Rather than strip this out, which requires lots of extra computation by converting a document into an object, we can optionally leave it in.
smartdevicelink/sdl_server,smartdevicelink/sdl_server,renonick87/sdl_server,smartdevicelink/sdl_server,renonick87/sdl_server