Merge pull request #425 from dbetebenner/master

Minor bugfixes in outputSGP
Change sequential implimentation to use appropriate data (.SD).  Change rqfit to allow data to be passed and return result instead of expression to be evaluated.
Cosmetic changes to make code more readable
Merge branch 'master' of github.com:SchoolView/SGP
Merge pull request #426 from dbetebenner/master

Update to 1.2-0.0 including weighted medians and scale scores for SGP targets
Merge pull request #427 from dbetebenner/master

More tests and bug fixes on updated scale score target functionality
Merge branch 'master' of github.com:SchoolView/SGP
Add in cohort size restriction to studentGrowthPercentiles, and needed additions to analyzeSGP and SGPstateData.
Merge pull request #428 from dbetebenner/master

Update of Guatemala SGPstateData
Add Utah SGP Norm Group Preferences
Merge conflict res
Merge pull request #429 from adamvi/master

Add SGP cohort size argument, UT SGPstateData updates for Norm group prefs and cohort size restrictions
Beginning of adding in targets to studentGrowthPlots and a bug fix from the scale score target calculation for lagged targets