Current status: Editmesh code is now completely gone. All references to editmesh functions have either been rewritten or commented out with //EDITBMESHGREP to enable easy grepping of things left to do. Mesh DNA has been changed to handle ngons with two new structures, MLoop and MPoly (MFace is deprecated). Old files are converted on load in do_versions(), however this is a little buggy. Changes to DerivedMesh have also been made; all the MFace functions are still there, but in addition functions for dealing with MPolys and MLoops has been added. No functionality for bmesh have been made other then the bare basic derivedmesh/conversion stuff, and even those are still incomplete/buggy.