- making oscimap default backend

- added about-screen
- added TreeTile for Tile lookup, dropping that HashMap
- using simple line-shader instead of std-derivatives one,
  about twice as faster here
- use distance calculation from MapRenderer - removing TileScheduler
- no need for MapGeneratorJob, pass MapTile directly to MapWorkers
- added two-finger tap gestures for zoom-in/out
- added tub/tron rendertheme
- started caching for oscimap
- add x/y coordinates to MapPosition, using it in MapRenderer
- create tag hash when needed
- no need for long tile coordinates max zoomlevel 31 should suffice

res/layout/activity_advanced_map_viewer.xml

@@ -11,17 +11,17 @@
         android:layout_width="fill_parent"
         android:layout_height="fill_parent" />
 
-    <ToggleButton
+   <!--  <ToggleButton
         android:id="@+id/snapToLocationView"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentRight="true"
-        android:layout_alignParentTop="true"
+        android:layout_alignParentBottom="true"
         android:layout_marginRight="10dip"
-        android:layout_marginTop="10dip"
+        android:layout_marginBottom="10dip"
         android:background="@drawable/snap_to_position"
         android:textOff=""
         android:textOn=""
-        android:visibility="gone" />
+        android:visibility="gone" />-->
 
 </RelativeLayout>