Blender Git Loki

Transform: Make snapDerivedMesh use bvhtrees from loose edges and bvhtrees from loose verts.

Bvhtrees take up a lot of memory space, reusing the common bvhtree of looptris to snap to vertices and edges is a good way to save memory.
Unfortunately we have a worsening performance in the snapping operation around 63% (addition to the original time).
But as we often do not need to build a bvhtree of loose verts and loose edges, we have an improvement in cache time :)

Since the CPU time of snapping operations (no matter how higth poly the object is) corresponds to less than 0.01% of all CPU time of a blender frame, that change is not really significant.

Snapping operations on a mesh in edit mode have not changed significantly.

Signed-off-by: Germano <germano.costa@ig.com.br>