DejaGnu: Handle the differing keys in SystemTap results

[petr-muller]

Some keys have a number in parentheses, but the testcase is the same

[petr-muller]

Perhaps add a .exp-level summary and diff by that as well.

[FilipMatys]

During import, is it important to keep PIDs as well?

[petr-muller]

Nope, we can throw away the PIDs