Reflect selected node in legend.

- Reflect current node selection in labels.
- Reflect current node selection in relationships.
- Remove label from inspector when selecting a node.

![oskar4j 2014-12-02 at 12 54 28](https://cloud.githubusercontent.com/assets/570998/5262209/fb7da8ec-7a22-11e4-8ccd-24d9767de3fa.png)
![oskar4j 2014-12-02 at 12 54 36](https://cloud.githubusercontent.com/assets/570998/5262210/fbb0eef0-7a22-11e4-9ec3-15000af452b7.png)
![oskar4j 2014-12-02 at 12 54 44](https://cloud.githubusercontent.com/assets/570998/5262211/fbb12686-7a22-11e4-97f4-d513bf64b4b1.png)