Fixed error in slide reference, Lesson 2 Residuals.
add note about stem and leaf plot printing to console
fix end of data vis lesson from data analysis
add yaml extensions to all lessons in rprog
add more flexibility to identical() question in rprog lesson
Removed UsingR and MASS dependency from Regression Models Introduction.
Removed UsingR package dependency from remaining lessons.
Merge branch 'master' into remove_usingr
minor change
fix typo
Merge pull request #39 from swirldev/remove_usingr

Remove UsingR package dependency
fixed vect, vect2 question in rprog