jQuery usage bugs & simplify HTML

On page load the expanded/contracted state of each line was unknown so on first click the action was not necessarily correct. It is a simple matter to use the icon-plus & icon-minus classes to determine the state.

In addition the use of the jQuery show effect was being incorrectly applied (should wait until the load has successfully run)

I also made jQuery do a bit more work to enable simplification of the HTML - ie. remove classes solely used as targets for jQuery (also added class to the 'No Children' line so that it can be styled as appropriate)