Added argument to return vector of scale scores to studentGrowthPercentiles
Bug fix from previous commit
Update of SGPstateData
Update of variables to NULL out to include SGP_NORM_GROUP_SCALE_SCORES and SGP_NORM_GROUP_BASELINE_SCALE_SCORES
Merge pull request #410 from dbetebenner/master

Update of studentGrowthPercentiles with new argument to output scale score vector