Estimate models and controllers

Adds the controllers for getting, updating and adding an Estimate as well as the Estimate, EstimateEntityManager, and EstimateModel classes. An Estimate is a code which has the name of the owner, the vote, the ID of the requirement, the ID of the estimate, and the ID of the owner. The managerLayer also now has a path in there for planningpoker/estimate. Changes from last commit: added the WPI-suite header to the classes