make end of tag path visible in distribution visualization

[jjacke]

This has already been changes for the tag cloud visualization, but it would also be helpful for the distribution graph: In the legend for the graph on the right side you only see the beginning of the tag path. Most of the time, however, it's the end that it interesting to the user. Right now there's no possibility to make the end visible. It should even be visible by default, I think.