fix pinchmap anchor warnings
Add some new layers

To make the QML GUI more usable until a proper list model corresponding to the map config is used, some of the new map layers were added.
Set main layer name when a layer is selected (so that the layer name is not undefined)
pretty print tile loading status messages
Long press of the back button now returns to the map screen at once (seem behaviour like in the GTK GUI)
Prepare to expose some modRana constants