Moved PayoffMatrix to import edu.nyu.cess.multi.common.games.pd.matrix
Created Matrix Choice
Created PlayerMatrixChoice
Added History view to RoundType
Moved PayoffMatrixProvider to package edu.nyu.cess.multi.common.games.pd.matrix
Added PayoffMatrix, PlayerMatrixChoices, StageState, and ViewTiming accessors and mutators

Functions to be deleted have been commented out
Renamed GroupChoice to GroupChoiceMatrix