Suspend/resume wont work properly with ForkTask

[fjtirado]

Current implementation is only valid for one suspended task at a given time, which might not be the case when using ForkTask

[fjtirado]

Also, publishing TaskSuspended, TaskResumend are misleading, since the task is not really suspended. Till interrupting a running task is implemented, those events won't be fired anymore.
Workflow suspended, resumed and cancelled events will be published as soon as a valid user request is performed, not when the task currently being executed finish.