Solidify modifier for Durian (allow cloth sim on single layer and make solid after)

Mostly the same as the recently added editmode tool with some extras.

* Options to disable filling in the rim between inner and outer surface, since its faster not to detect this in cases where its not needed.
* Option to disable high quality normal calculation, mostly noticable when operating on building walls, not needed for cloth or more organic shapes.
* Option to disable 'even thickness', again, not needed in some cases.

Also options for creasing inner/outer and rim edges, need this for makign Sintels cloths solid since zero crease looks far too soft.

note:
* UVs and VCols etc are copied to the new skin however rim faces dont get the UVs or vcols set from the faces they are created from yet.
* Normals are assumed to be pointing outwards
* used patch from Uncle Entity as a template since it added the DNA and RNA entries but the actual modifier from the patch wasnt used.

release/scripts/ui/properties_data_modifier.py

@@ -600,6 +600,20 @@ class DATA_PT_modifiers(DataButtonsPanel):
     def SOFT_BODY(self, layout, ob, md, wide_ui):
         layout.label(text="See Soft Body panel.")
 
+    def SOLIDIFY(self, layout, ob, md, wide_ui):
+        split = layout.split()
+
+        col = split.column()
+        col.prop(md, "offset")
+        col.prop(md, "use_rim")
+        col.prop(md, "use_even_offset")
+        col.prop(md, "use_quality_normals")
+        col.prop(md, "edge_crease_inner")
+        col.prop(md, "edge_crease_outer")
+        col.prop(md, "edge_crease_rim")
+        # col.label(text="Vertex Group:")
+        # col.prop_object(md, "vertex_group", ob, "vertex_groups", text="")
+
     def SUBSURF(self, layout, ob, md, wide_ui):
         if wide_ui:
             layout.row().prop(md, "subdivision_type", expand=True)