Merge pull request #675 from dbetebenner/master

Updating SGPstateData
Add sgPlot.reports.group.vars argument to visualizeSGP
Merge branch 'master' of github.com:CenterForAssessment/SGP
Fix school name selection when NA's exist.
Merge pull request #676 from dbetebenner/master

Updates to accommodate WIDA_MI
Merge pull request #677 from dbetebenner/master

Update of SGPstateData
Merge pull request #678 from dbetebenner/master

Updates of RLI_UK and MI SGPstateData
Check for when calculate.simex is FALSE (same as NULL)
Merge branch 'master' of github.com:CenterForAssessment/SGP
Updates for 2014 GA analyses
Merge pull request #679 from adamvi/master

Updates for 2014 GA analyses
Fix SGPstateData merge conflict
Merge pull request #680 from adamvi/master

Fix SGPstateData merge conflict
Merge branch 'master' of https://github.com/CenterForAssessment/SGP
Adding documentation to visualizeSGP