[daisy] Navigation tree enhancements

[Bruno Dumon]

Hi,

I've implemented a couple more improvements for the navigation trees
(see [1] for the original ideas and [2] for previous enhancements).

The changes are:

* query nodes can now have child nodes, the child nodes will be executed
for each query result. This allows for things like importing all
navigation trees satisfying a query, nested queries, building link nodes
dynamically, ...

* a new "separator" node has been added, by default simply rendered as a
line between two nodes. Separator nodes are automatically hidden if two
or more would appear in a row, or when they would appear as first or
last child of a node.

* contextualized trees can now be expanded up to a certain configurable
depth (previously nodes outside the active navigation path were always
expanded up to depth 1). This can be configured with a tag
navigationDepth in the siteconf.xml.

I'll add more detailed information about these to the documentation.

[1] http://lists.cocoondev.org/pipermail/daisy/2006-September/004948.html
[2] http://lists.cocoondev.org/pipermail/daisy/2006-September/005121.html

-- 
Bruno Dumon                             http://outerthought.org/
Outerthought - Open Source, Java & XML Competence Support Center
bruno at outerthought.org                          bruno at apache.org