- replaced all calls to commandManager.addCommand with firing of "newOperation" events: this way any other element can listen to those events, increasing decoupling
- replaced all calls to commandManager.addCommand with firing of "newOperation"
events: this way any other element can listen to those events, increasing decoupling

- experimental : added removal of right hand operands for subtract boolean operations:
 does make more sense visually, but not too sure yet

usco/usco-proto