RFR: 8036599 Use Diagnostic Commands instead of SA by default in jinfo

[Staffan Larsen]

The jinfo utility has three flags: 
-flag: set/get value of a JVM flag
-flags: print all JVM flags
-sysprops: print all System.properties

Currently -flags and -sysprops invokes the Serviceability Agent to get the information. Given how intrusive the SA is this is not ideal. I have changed the default implementation for these flags to instead use Diagnostic Commands through the attach framework (this is also what -flag uses). If you still want to run the SA, you can do so by specifying -F (or by running on a core file). 

I have changed quite a bit of the (still) hairy argument parsing. The single basic test for jinfo has also been updated so that all flags are now exercised on all platforms (not just where SA is available).

webrev: http://cr.openjdk.java.net/~sla/8036599/webrev.00/
bugs: https://bugs.openjdk.java.net/browse/JDK-8036599

Thanks,
/Staffan