support for network partitioning tests.

in network partitioning tests if mirror server is zapped and rejoins stripe as a mirror after network is restored the galvan is throwing FATAL GALVAN EXCEPTION:

[Interlock] serverBecamePassive: Server "testServer1": d6e3f690-fe3f-4160-ae39-b28a1544d85f (has been zapped: false)
FAIL USING Server "testServer1": d6e3f690-fe3f-4160-ae39-b28a1544d85f (has been zapped: false)
org.terracotta.testing.master.GalvanStateInterlock@f130959
Active: Server "testServer0": 98338ef4-5d02-40c9-b17a-bce60504f21d (has been zapped: false)
Passives: [Server "testServer1": d6e3f690-fe3f-4160-ae39-b28a1544d85f (has been zapped: false)]
Unknown: []
Terminated: []
Clients: [Thread[Thread-5,5,main]]
XXXXX FATAL GALVAN EXCEPTION IN HARNESS! TERMINATING PROCESS! WARNING: Stale java processes may remain!
java.lang.AssertionError: Case expected to be true
at org.terracotta.testing.common.Assert.assertTrue(Assert.java:26)
at org.terracotta.testing.master.GalvanStateInterlock.localAssert(GalvanStateInterlock.java:424)
at org.terracotta.testing.master.GalvanStateInterlock.serverBecamePassive(GalvanStateInterlock.java:255)
at org.terracotta.testing.master.ServerProcess.didBecomeActive(ServerProcess.java:303)
at org.terracotta.testing.master.ServerProcess.access$200(ServerProcess.java:45)
at org.terracotta.testing.master.ServerProcess$3.onEvent(ServerProcess.java:284)
at org.terracotta.ipceventbus.event.DefaultEventBus.sendLocal(DefaultEventBus.java:65)
at org.terracotta.ipceventbus.event.DefaultEventBus.trigger(DefaultEventBus.java:59)
at org.terracotta.testing.common.SimpleEventingStream.write(SimpleEventingStream.java:53)
at java.io.OutputStream.write(OutputStream.java:116)
at org.terracotta.ipceventbus.io.MultiplexOutputStream.write(MultiplexOutputStream.java:109)
at org.terracotta.ipceventbus.io.Pipe$1.run(Pipe.java:45)

Attached 4 logs: console output, active server log and 2 mirror server logs.
Note: this Exception is causing orphan server processes left behind