RFR(s): 8035001: TEST_BUG: the retry logic in RMID.start() should check that the subprocess hasn't terminated

[Stuart Marks]

Hi all,

Moar RMI test cleanups!
The main issue is that the timing loop that waits for rmid to start will now 
check to make sure the process hasn't exited prematurely.

I've also taken the opportunity to simplify this and other timing loops in the 
RMI test library and to make their elapsed-time output more consistent.

Webrev:

        http://cr.openjdk.java.net/~smarks/reviews/8035001/webrev.0/

Bug:

        https://bugs.openjdk.java.net/browse/JDK-8035001

thanks,

s'marks