Merge pull request #1 from jcheng5/master

Datasets should be stored as reactive values
Version 0.03
Using Joe's reactiveValue suggestions
Minor
added a dev app. the damshiny app will be updated when shiny features are added in a new release (0.25?)
Using action buttons to add variables to the data
Trying to figure out isolate and the action buttion
Fixed README.md
License info in README.md
Using a checkbox for adding residual to dataframe. Can't get action button to work
Using action button to save residuals
file.choose working with action button
Searching for the circular reference in regression estimation
Move button handling code to own observer