adding positive, negative endpoint at the end of connection , work in progress
handler added in con-author for check expression
code cleanup in con-author
added method to put + or - label at the end of connection endpoint
Merge branch 'pradeep'
Move buttons to use screen real estate better.
Change html for dijit/form/Button to be uniform and match Dojo
documetation.
Update equation labels more consistently.
Fix bug where node positions not saved to model in AUTHOR mode.