Diagnostic command fixes

[Nils Loodin]

Hey all!

The new diagnostic command parser needs some additional specializations for time and bytes, here included.
Also a few fixes for crashes for some combinations of commandlines.

Tested by throwing a lot of different arguments on the parser, also by running the tests in sun/tools/jcmd.

http://cr.openjdk.java.net/~nloodin/7145243/webrev.00/

I would also need a sponsor to get this in..

Regards
Nils Loodin