Expose new Recast partitioning methods for navmesh generation

This patch depends on D1747, which upgrades the Recast version.  It exposes the new Recast partitioning methods in the navmesh generation.

Reviewers: campbellbarton, moguri

Reviewed By: moguri

Projects: #bf_blender

Differential Revision: https://developer.blender.org/D1748

release/scripts/startup/bl_ui/properties_game.py

@@ -510,7 +510,11 @@ class SCENE_PT_game_navmesh(SceneButtonsPanel, Panel):
         col.label(text="Region:")
         row = col.row()
         row.prop(rd, "region_min_size")
-        row.prop(rd, "region_merge_size")
+        if rd.partitioning != 'LAYERS':
+            row.prop(rd, "region_merge_size")
+
+        col = layout.column()
+        col.prop(rd, "partitioning")
 
         col = layout.column()
         col.label(text="Polygonization:")