drawMappedEdges - added DerivedMesh.convertToDispListMeshMapped function which converts and also returns mapping information for use in editmode - updated DispListMesh derivedmesh to be able to function in editmode - update mirror modifier to support use as a cage - update mirror & subsurf modifiers to properly pass mapping information down modifier stack It is now possible to have a mesh with mirror/subsurf modifiers where you can edit with both as cage. Selecting the mirror'd part works, but of course transform is flipped so it is a bit weird. Not the cleanest code in the world and I can't say I am really happy with the architecture but it works for now and supports the existing feature set.