RFR 8024055: serviceability/attach/AttachWithStalePidFile.java createJavaPidFile() fails

[Jaroslav Bachorik]

Please, review the following test change

Issue : https://bugs.openjdk.java.net/browse/JDK-8024055
Webrev: http://cr.openjdk.java.net/~jbachorik/8024055/webrev.00

This request is a follow-up to the stalled review request 
http://mail.openjdk.java.net/pipermail/serviceability-dev/2014-October/015785.html 
(the issue has changed its owner since then)

As stated in the original request:
"
This patch fixes two intermittent issues seen over the past year:

   a) Possible failure where an existing pid-file is not owned by the 
test user
   b) Race during startup where we try to attach to the target before 
it’s ready (removed arbitrary 5sec sleep)
"

This version is addressing David's comment about better processing the 
target process' stdout directly and not asynchronously.

Thanks,

-JB-