The overloaded member signal just hit us, to use it is a pain
but the resuting code is faster and less error prone, so it's
still a good thing to do.
Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>

Updated Google Maps API Version
Updated User Agent used for map tile requests

It was introduced by the Open Pilot URL Factory code.

Restructured to better fit existing build structure

Added Bing Hybrid Map
Added Open Street Map
Set map selection menu checks (exclusive check)
Handle proper image type otherwise disk caching fails

As this is no longer google specific, renamed everything google to qgc.