RFR: Make ShenandoahOWST option default

[Aleksey Shipilev]

On 11/08/2016 10:34 PM, Zhengyu Gu wrote:
> Webrev: http://cr.openjdk.java.net/~zgu/shenandoah/default-owst/webrev.00/

Actually tried it today in one of my tests, and it turned out great.
Let's enable.

Two comments though:
 a) Can we leave it experimental though? This will indicate we trust it,
but not completely;
 b) Can you put down something more descriptive in flag description?

Thanks,
-Aleksey