need to filter the authors; the CRAN page is not correct: http://cran.r-project.org/web/packages/knitr/citation.html
use the `@include` tag to prepare the upcoming changes in roxygen2 (Collate will be gone)

klutometis/roxygen#139
expose the code option and make it possible to generate the code chunk programmatically
add AsciiDoc and Textile to the reference card, and use smaller fontsize for the table
bump version