Some code review changes.

 - Add add_branch method to a feature
 - Add references to creating plugins in Branch and PlanningInfo classes.
 - Rename CIInfo to BuildInfo.
Finish previous commit (:S)
Add docs.
Final pieces of code review.
Add future TODO.
Add description to the planning interface...
Merge branch 'dev_alex' of git+ssh://github.com/pretenders/deploystream into dev_alex