[safety-maintenance] Automatic modification detection (change in GSN)
Solves following issue: #3744
Add to the maintenance status also "modified".
When a GSN node undergoes a change,
the referencing GSN node is to be annotated as “modified”.
(from redmine: issue id 3744, created on 2019-06-04)
- parent #3009
Also,some bugs regarding the propagation of impacted elements were also fixed. Propagation of impact is now available also for modified elements.