cleared ipynb output
Customized lessons page for 2013-09-chicago bootcamp and added link to it on main webpage.
Returned flow-control and functions-and-modules notebooks back to June 2013 state.
Updated jokes and file paths.
Added intro R materials.
Added links to R materials on lessons page.
Merge branch 'gh-pages' of https://github.com/jdblischak/2013-09-19-chicago into gh-pages