* Created GmapsGeoModelAdmin to replace OpenLayers widgets in admin
* Added more options (behaviour key) to widget
* Added the 'address' key options
* Updated the widget media to a dynamic property
* Renamed from 'gmapsy' to 'gmaps'
Changed from dict attributes to a GmapAttributes class id ModelAdmin class, and many features
 - add suport to modifiable option
 - add suport to address geocoding