Merge pull request #662 from dbetebenner/master

Merge of Adams branch and additional pieces
Fix sequential production of sgPlots by district/school and update documentation
Update WA baseline matrices and norm group preferences
Merge pull request #663 from adamvi/master

Fix sequential creation of student growth plots in visualizeSGP and update SGPstateData
Merge branch 'master' of https://github.com/CenterForAssessment/SGP