previous code created faces with mixed face-flipping and could get very slow,
test with ~60,000 edges here hung my system for over 2min (didnt wait for it to finish), new code executes in about 1 second.
new code doesn't attempt to flip faces correctly, its quite involved to do so, especially when the new faces are not created adjacent to eachother.
so simpler to calculate normals afterwards.
- calc normals only check flag when needed.
- keymap, dont get name unless its needed.
- keymap, avoid property lookup.
- idprop debug print, include pointer, helpful for troubleshooting.
- normals depended on the meshes rotation, so you could rotate Suzzane and in some cases one of the eye normals would be flipped.
- normals depended on the meshes placement in relation to the meshes center, now find the outer most face by each face-island center.
