Krun options

**please review**

* use JCommander for krun
* clean up krun frontend to be more generic
* fix some hacky behavior in some of the options
I don't understand what's the issue here... I think Radu is right to require no program for the definition. For ktest to work all one needs is a program which parses, even if the program is not used in the configuration.  We already have other tests which behave similarly...