Blender Git Loki

Multi-Objects: MESH_OT_dupli_extrude_cursor

Supporting the ctrl+click operator for multiple objects.
When no vertex is selected we only add a new vertex for the active object.

I'm using all the selected vertices to calculate the center of transformation
regardless of the object they come from. This way we have the same effect if the
meshes are joined together or kept as individual objects.

Thanks Campbell Barton for reviewing the patch.