Merge pull request #522 from adamvi/master

Update GA LOSS/HOSS Values and add key check in SIMEX function
Adding sgp.loss.hoss.adjustment modification
Update of loss.hoss.adjustment
Refinement of loss.hoss adjustment
Merge pull request #523 from adamvi/master

Update/Add calculate.simex and calculate.baseline.simex defaults and documentation
Merge branch 'master' of https://github.com/CenterForAssessment/SGP
Merge pull request #524 from dbetebenner/master

Refinement of Loss/Hoss adjustment
Merge branch 'master' of github.com:CenterForAssessment/SGP