RFR: JDK-8199700: SA: Enable jhsdb jtreg tests for Mac OS X

[Jini George]

Requesting reviews for enabling SA tests on OS X for Mach5.

https://bugs.openjdk.java.net/browse/JDK-8199700

Webrev: http://cr.openjdk.java.net/~jgeorge/8199700/webrev.00/

The changes are mostly to include the addition of sudo privileges to the 
SA launchers for OSX if Platform.shouldSAAttach() fails. Some tests 
(those using clhsdb) have been refactored to use ClhsdbLauncher for ease 
of maintainence. This also avoids checks for Platform.shouldSAAttach() 
for corefile related test cases. More details have been provided in JIRA.

Thanks,
Jini.