Add {excerpt} sections to all doc chapters with children

We need to order the doc chapters. Cris mentioned that he will woprk on that, still opening this for tracking purposes:

http://objectstyle.org/cayenne/lists/cayenne-devel/2006/05/0062.html

BTW, I created a Wiki page documenting the procedure:

http://objectstyle.org/confluence/display/CAY/Documentation+Guidelines

Also related: CAY-555