Manipulator: view3d navigation buttons

Added for Blender101 template.
Disabled by default, enable as a preference.

Exposes rotate, pan, zoom, persp-ortho & camera toggle.

release/scripts/startup/bl_ui/space_userpref.py

@@ -287,6 +287,7 @@ class USERPREF_PT_interface(Panel):
         #col.prop(view, "open_left_mouse_delay", text="Hold LMB")
         #col.prop(view, "open_right_mouse_delay", text="Hold RMB")
         col.prop(view, "show_manipulator")
+        col.prop(view, "show_manipulator_navigate")
         ## Currently not working
         # col.prop(view, "show_manipulator_shaded")
         sub = col.column()