Blender Git Loki

Orange: Display types and variable size for Empties.

This is using instructions from Ton, so hopefully the implementation is ok.
This is really needed here where we are using all sorts of wacky scales, and
empties look too big or too small. Of course we don't want to scale the
empties because there are often things parented to them.

New options are in edit buttons for empties to control the display style
and the size. New styles are easy to add, too. Just needs useful ideas and
minor effort from anyone who wants to.

Support for copying these values has also been added to the Copy Attributes
->Drawtype menu command.