Blender Git Loki

Fix (IRC reported) DataTransfer modifier affecting base mesh in some cases.

Checking only whether mverts is same as base mesh one is not enough in
all cases, some modifiers (deform ones) can only generate new mvert
data, while keeping others from original mesh.

Now checking both mvert or medge, hopefully this will be enough to catch
all problematic cases this time.

Thanks @gaia for finding that problem. :)