Unit Tests - abbreviation, filter, benchmark

- Added tests for attribute abbreviation.
- Added tests for filter permutation testing.
- Added benchmark for ongoing performance measurement.
- Mentioned test suite in docs.  Why not?

html/task.html

@@ -119,6 +119,8 @@
                   <li>Fixed bug with the task sort alogrithm, which led to an unstable sequence
                       when there were only a handful of tasks.
                   <li>Performance enhanced by eliminating unnecessary sorting.
+                  <li>Task now has a large (and growing) test suite and bug regression tests
+                      to help ensure higher quality releases.
                 </ul>
 
                 <p>