overhaul of the category display: it is now able to display multi-level deep categories, use cattree.css instead of mktree.css for a more dense display of the category tree in tree style (see category-procs.tcl for the whole path).
providing means to store xotcl objects in the CR; using such an object to configure xowiki; editing wiki objects require admin permissins on the folder; setting "index_page" in admin object uses this wiki page as start page; improved admin interface; made categories pluging more robust for relative paths