Extension:Graphical Category Browser

Why is this extension necessary?
Showing the interconnection of categories as a graph enhances navigability of the site.

What this extension does

 * A special page "Graphical Categories Browser" is added.
 * A graph is added on top of each category page showing the relationships to other categories.

Images are file cached. Cache control to match html and image output is supplied.

Installation

 * Install Graphviz - Graph Visualization Software.
 * Download script and copy to to extensions.
 * Correct $xyDotPath and $xyCategoriesCache to Your needs.
 * Create directory images/xyGraphvizCache
 * Add the following line to LocalSettings.php

Category Page
Change the hook for the category page to show all up- and downstream connected categories.

Special Page Category Errors
Show errors in categories:
 * cycles