Fix Issue #0002277: render no longer produces vaild tk tags.
Fix Issue #0002504: <graph> addedge <tail> <head> using node handles takes wrong head.
apply patch from csanchezdll - <graph> addedge <tail> <head> using node handles
takes wrong head
Merge pull request #29 from csanchezdll/master

Fix Issue #0002277: render no longer produces vaild tk tags.