RFR [9]: Bulk backports to sh/jdk9

[Aleksey Shipilev]

http://cr.openjdk.java.net/~shade/shenandoah/backports/jdk9-20171101/webrev.01/

Changes include:

rev 13731 : [backport] Control loop should wait before starting another GC cycle
rev 13732 : [backport] SieveObjects -UseTLAB config timeouts
rev 13733 : [backport] Stop string dedup thread during VM shutdown

Testing: hotspot_gc_shenandoah

Thanks,
-Aleksey