We also need some tests for the "tail" command.

TODO.txt

@@ -1,6 +1,6 @@
-- The new fg command in supervisorctl has tests to verify its error handling
-  but not its operation.  We should add some additional tests to verify its
-  operation for completeness.
+- Both the "tail" and "fg" commands in supervisorctl have tests to verify
+  their error handling but not actual operation.  We should add some additional 
+  tests to verify their operation for completeness.
 
 - Finish process group reloading that was merged into trunk. We decided to
   implement addProcessGroup() such that at the time it is called, it reads the