Bug fixes:
- Warning symbol when Concuerror execution is canceled and there is no result
  for the track being executed
- The shown element number is now based on the action number
Minor cleanup and changes such as:
	- Changed text of action nodes to show "Action N" and not "Element N"
	- Eliminated comments for every action node indicating the number
	- Warning now correctly shown when Concuerror is stopped and there is no
	  result for the branch it was exploring
	- Added "vee" edge
Changed 'element' to 'event'
Changes to viconc.py:
	- imports are all now on the top of the file
	- slight refactoring
Added OSS