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.