Adds Sprint Board

This duplicates the Workboard classes in the Project application
Sprint Board = Workboard ++
The SprintProjectProfileController overrides the PhabricatorProjectProfileController for all Projects
Adds points to Sprint Board Task Cards
Allows for further modification of Sprint Boards within the Sprint application context

Change-Id: Ic454e1624e34cedd0cb24cbcbc8ed42542596af7
Adds new JS behavior for Sprint Boards

Renamed Burndown Controller to Sprint Controller
Removed Inheritance from PhabricatorProjectController for Board Classes

Change-Id: I5ba5160e66a1bbc2325d4357606cd3e4496caf45
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/storage/SprintBuildStats.php