Add a basic smoke test.

This should help with the refactoring.
Move the writecfg function outside Configure.
Move the rollback function outside Configure.
Move the testfail function outside Configure.
Move the tostring function outside Configure.
Minor cleanups in the tostring method.
Remove unused variable.
Remove warnings on SL6.

There were lots of constructions %$foo->, and duplicate variable
declarations, which are deprecated and wrong.  Declare variables only
once and replace hash dereferences with $foo->.
Remove incomplete comments.
Do not raise errors if files are created for the first time
Merge pull request #82 from piojo/shorewall-sl6

Make ncm-shorewall work on SL6.