Fix regex in lettuce tests

The old version with . didn't work well with the form
  wait … for MESSAGE not OTHER_MESSAGE
Since the whole "MESSAGE not OTHER_MESSAGE" was captured into the first
(.+). This broke several tests in around xfrin and possibly others.

Now the tests pass and reviewed on jabber.

tests/lettuce/features/terrain/steps.py

@@ -30,7 +30,7 @@ def stop_a_named_process(step, process_name):
     """
     world.processes.stop_process(process_name)
 
-@step('wait (?:(\d+) times )?for (new )?(\w+) stderr message (.+)(?: not (.+))?')
+@step('wait (?:(\d+) times )?for (new )?(\w+) stderr message (\S+)(?: not (\S+))?')
 def wait_for_stderr_message(step, times, new, process_name, message, not_message):
     """
     Block until the given message is printed to the given process's stderr