Easy to find commit on network graph.

1. Commit on network graph is marked and displayed in the center
2. Add link to netwok on commits page and commit page.

### Screenshots

![marked_commit_on_network_graph](https://f.cloud.github.com/assets/72138/115417/74879fe6-6bce-11e2-9939-febba5cab773.png)

![link_to_network_on_commits](https://f.cloud.github.com/assets/72138/115420/7cb069b4-6bce-11e2-9f80-228840bd3813.png)

![link_to_network_on_commit](https://f.cloud.github.com/assets/72138/115424/85520dc0-6bce-11e2-981f-550ce2796747.png)