Link concepts in graph

[jpwiedekopf]

Currently, the graph windows do not interact with the main UI. It is not possible to show a concept in the graph in more detail, or to invoke the neighborhood display for a different concept to the current focus concept.

The current workflow to examine a new focus concept, which was "discovered" from the neighborhood graph is involved:

1. note the code of the new focus concept
2. change the window focus back to the main window
3. check if the filter at the top of the concept diff has to be adjusted
4. search for the concept using the fuzzy matcher
5. scroll through the list of close matches (since the search is fuzzy, this might be somewhat long), and find the new focus concept in the result list
6. invoke the desired action, i.e. view the neighborhood graph, the properties, etc.

It should be possible to add actions for inspecting a concept to the graph views.