Issue was, when requesting (building) lnors for a mesh that has
autosmooth disabled, one would expect to simply get vnors as lnors.
Until now, it wasn't the case, which was bad e.g. for normal projections
of loops in recent remap code (projecting along split loop normals
when you would expect projection along vertex normals...).
Also, removed the 'angle' parameter from RNA's `mesh.calc_normals_split`.
This should *always* use mesh settings (both autosmooth and smoothresh),
otherwise once again we'd get inconsistencies in some cases.
Will update fbx and obj addons too.
Mesh stores its dvert in a specific pointer too, in addition of regular CD layer...
That whole vgroup handling is really breaking apart the 'universality' of CD system. :(
Also added some DAG and WM updates in operators...
