initial font-awesome import
Merge pull request #332 from jcheng5/bugfix/no-html-class

Fix test breakage due to HTML() missing from rendered output
integrate icons into the rest of the ui
re-roxygenize
fix R CMD check documentation errors
Merge remote-tracking branch 'origin/master' into feature/font-awesome
update NEWS
Merge pull request #334 from rstudio/feature/font-awesome

icon function for embedding icons from the font-awesome icon library
Features for easier explaining of reactivity

- makeReactiveBinding: Turns a "regular" variable into a reactive.
  No need to use reactiveValues() for simple reactivity.
- setAutoflush (not exported): Causes flushReact() to be called
  each time something is executed at the R console top-level.
- options(shiny.suppressMissingContextError=TRUE): Prevents the
  "Operation not allowed without an active reactive context" error
  when attempting to read a reactive value or expression from the
  console.
Incorporate code review feedback from @yihui
Fix example