Bug 2812

After creating a new session with several processes, and 4-5 observers, exiting
the assistant brings up the MainWindow with errors:

Failed to add tasks observer

frysk.gui.monitor.SessionProcDataModel$1.addFailed(FryskGui)
frysk.proc.OffspringObserver$1.execute(FryskGui)
frysk.event.EventLoop.runEventLoop(FryskGui)
frysk.event.EventLoop.run(FryskGui)
frysk.gui.Gui$4.run(FryskGui)
java.lang.Thread.run(libgcj.so.7)

Followed by (several times):

{frysk.proc.LinuxTask@5dc9cc0,pid=30756,tid=30756,state=running} in state
"running" did not handle handleAddSyscallObserver

frysk.proc.State.unhandled(FryskGui)
frysk.proc.TaskState.handleAddSyscallObserver(FryskGui)
frysk.proc.Task.handleAddSyscallObserver(FryskGui)
frysk.proc.TaskSyscallObservation.handleAdd(FryskGui)
frysk.proc.ProcState$3.handleAddObservation(FryskGui)
frysk.proc.Proc.handleAddObservation(FryskGui)
frysk.proc.Proc$7.execute(FryskGui)
frysk.event.EventLoop.runEventLoop(FryskGui)
frysk.event.EventLoop.run(FryskGui)
frysk.gui.Gui$4.run(FryskGui)
frysk.gui.Gui$4.run(FryskGui)
java.lang.Thread.run(libgcj.so.7)

After which, I get:

{frysk.proc.LinuxProc@f37c80,pid=30756,state=running} double state transition

frysk.proc.Proc.oldState(FryskGui)
frysk.proc.Proc.handleAddObservation(FryskGui)
frysk.proc.Proc$6.execute(FryskGui)
frysk.event.EventLoop.runEventLoop(FryskGui)
frysk.event.EventLoop.run(FryskGui)
frysk.gui.Gui$4.run(FryskGui)
frysk.gui.Gui$4.run(FryskGui)
frysk.gui.Gui$4.run(FryskGui)
java.lang.Thread.run(libgcj.so.7)

Which finally results in the last few processes in the MainWindow appearing with
no observers attached; usually only the first one or two.