Making 0 a non-valid final estimate

Making 0 an invlaid choice for the final estiamte, updateing fields
accordingly

Authors: lhunker, ammesonb
Merge remote-tracking branch 'origin/team9dev' into final_estimate
Adding note field to GUI

Adding a note field to the completedRequirement panel

Author: lhunker, ammesonb
Adding an estimateNote field to gamerequirementmodel

Adding estimate note field and related getters and setters

Authors: lhunker, ammesonb
Notefield updates to/from server and estimate population fixed

Notefield is saved to the server, and populates from the server. Final
population field only populated with mean if the user is the owner and has
not set an estimate

Authors: lhunker, ammesonb
Validates note field for final estimates

If modifying first final estimate, requires note with
at least one non-whitespace character.

Authors: ammesonb, lhunker
Adds note signifying manual change

Author: ammesonb, lhunker
Adds 1 missing comment

Author: lhunker
Merge pull request #90 from dbeckwith/final_estimate

Final estimate