Initial commit

The first ideas on dependency graphs for the Stacks project.
Now the force-directed graphs are generated

There are still plenty of rough edges.
Names for tags are now taken into account
Implemented heat mapping in force directed graph
More goodies for the graphs

* cluster view uses the same information as tree view, hence we do this
* small updates to the force directed (recolouring doesn't work yet)
* restructured parse.py
* tree view is now dynamically loaded
Types in the cluster view

Making it clickable is impossible for now...
Rudimentary scroll to center
Code for the collapsible layout

With chapters and sections. But the one including sections might not be
brilliant the way it is right now.
Fixed bug in the createGraph method

And I hopefully improved the createPacked method
Speed up getChildren

It's still not amazingly fast, but hey.
Why one-lines are evil

Sometimes the one-liner is not the fastest option...
Implemented dynamic window size and autoscroll

The parameters might need a little tweaking depending on the final
output size. Maybe it would be a good idea to write the number of nodes
to the database (as this is also interesting statistical information,
and it will be necessary to display the warning to the users.
Updates to the force-directed graph

* indication of root node
* better colours for types
* left / right click for navigation in graph
General cleanup of the graph.php file
Implemented color switch in force-directed graph
Better layout for force directed controls
Implemented legend for force directed
Improved force directed

Implemented colorChapters (but not yet satisfied with it, and that is
something for later) and a decent legend / toggle.
Created a legend for the heat mapping
Implemented tooltip

It could be better, but it's time I focus on the other graphs.