Tags filtering added to the Common Lisp Directory

As the content of the Common Lisp Directory continues to grow (263 items now) it's useful
to be able to filter it somewhat.

How to use it:

0 log on to see the filter (will be extended to anonymous users later)

1 Click on the first triangle/arrow and select one or more tags (start with only one to
test, "Books" for instance) If they are several tags, all of them will be required

2 Click apply filter

3 Click on the second triangle/arrow to select another color.

4 Click apply filter

5 Check the check box and apply the filter again

6 report bugs, improvements, comments, etc. ;-)

Marc