*** Description of problem:
For sequence flows outgoing from some gateways can be specified condition expression. Editor for this expression doesn't contains negative variants.


*** Version-Release number of selected component (if applicable):
6.2.0.ER3


*** Steps to Reproduce:
1. Create process with for example inclusive gateway
2. Click on sequence flow outgoing from this gateway
3. Open condition expression editor in properties bar

*** Actual results:
There are only conditions like:
- is equal to
- is null
- is empty


*** Expected results:
There should be also expressions like:
- not equal to
- not null
- not empty