add 'deform - integrate' option to mesh-cache,

This means the deformation on the input to the modifier can be re-applied ontop of the mesh cache.

In practice this is most useful for using corrective shape-keys with mesh-cache.

release/scripts/startup/bl_ui/properties_data_modifier.py

@@ -168,6 +168,7 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
 
         layout.label(text="Evaluation:")
         layout.prop(md, "factor", slider=True)
+        layout.prop(md, "deform_mode")
         layout.prop(md, "interpolation")
 
         layout.label(text="Time Mapping:")