[JENKINS-16356] Show seed job and template job info in the generated job

Covers JENKINS-16356 and JENKINS-16357.

Sample result:
![image](https://cloud.githubusercontent.com/assets/1336981/5404267/22711652-818d-11e4-815a-b2f4a4aa0e0c.png)

That's because I'm following the convention of updateTemplates() method hence I'm extending the SeedReference. Do you think I should split that two apart? Wanted to make SeedReference abstract for clean code sake but it will break backward compatibility.