SERVER-15535 Make all calls to exitCleanly but the first hang forever.

Some components, notably the replication coordinator, cannot be shutdown
repeatedly, but also may not be shutdown while holding the global exclusive
lock.  With this change, only one call to exitCleanly will proceed to
completion; all others will spin in a long sleep loop, neither returning nor
engaging in shut down tasks.
SERVER-15535 Wait for secondary to start and replicate in jstests/replsets/initSyncV1Index.js
Merge remote-tracking branch 'upstream/master'