Blender Git Loki

Made another attempt to fix degenerate triangles in imported mesh data.

This commit replaces the solution in revision 44539.

It is recalled that a degenerate triangle is a triangle such that
1) A and B are in the same position in the 3D space; or
2) the distance between point P and line segment AB is zero.

Degenerate triangles in the second form are now resolved by adding a
small offset to P (i.e., the resulting triangles have a non-zero area).