Added basic Map widget to add location of resources

Now we can add *location* to resource of metastudio project.

**Adding location :**
 1.  When we are editing or creating new resource, click on ```Add Location``` (in Edit now) to call map overlay.
 2.  Default view of map is Europe-Asia. So zoom into desired map location.
 3.  Now add location marker - Left Click on map. That's it !
 4.  If you feel that added marker is not at appropriate position then you can (Left Click) drag it to desired location.

As this widget is in primary stage, contains basic features to add location into map. But as development proceeds large set of features will be added to it. 
**Following is the list of some features :**
 - Allowing user to delete added marker/s.
 - Adding some info about marked location.
 - Implementing Search of locations.
 - Adding Lines, Polygons etc.