Result: Elections will not proceed correctly until heartbeats are processed.

Repro:

1. fsyncLock() secondary (XXX:27019)
2. raise the priority for the PRIMARY (XXX:27017) and issue rs.reconfig()
3. shut down the PRIMARY
4. observe that another SECONDARY (XXX:27018) cannot be elected since the fsyncLock'ed one vetoes it:

   Wed Oct  9 11:58:21.339 [rsMgr] not electing self, XXX:27019 would veto with 'XXX:27018 is trying to elect itself but XXX:27017 is already primary and more up-to-date'
   

5. fsyncUnlock() the SECONDARY ( XXX:27019 ), observe the XXX:27018 being elected

Expected behavior:
Write locks should not prevent an election or delay detecting replica set node state changes. This message is an example:

Wed Oct  9 11:51:01.864 [rsHealthPoll] replSet member XXX:27017 is now in state DOWN

Ideally, XXX:27019 should vote for XXX:27018 (see SERVER-11059).