[GUI] Icon for strongly causal
Steps to reproduce:
- create a project
- create a component architecture
- create a component
- click on the component
- in the properties, check “Strongly Causal” checkbox
Observe: the component is now blue in the editor
Expected:
- component colour does not change (i.e., still yellow as for weakly causal)
- icon changes to have a little “s”
(from redmine: issue id 2592, created on 2016-05-25, closed on 2016-07-18)