[qmtest] adding context variables in a target extension class

[Mark Mitchell]

> I need to pass a bunch of node hostnames associated with a particular 
> test target to shell script tests that implement a distributed system 
> test case. These hostnames must be parameters to the test harness, so 
> as near as I can tell they have to be passed either in the QMTest 
> context file or as attributes to a target extension class.

I think using a target extension class is appropriate.

-- 
Mark Mitchell <mark at codesourcery.com>
CodeSourcery, LLC