the background color can be set in either latex or html
a helper function pandoc_to() to return the rmarkdown output format
closes #772: add knit_print.knit_asis as an identity function
factor out ncol(x)
closes #771: `digits` can be a vector in kable()
add the chunk option R.options; closes #764
closes #757: use hook_purl to write out code while weaving; this will probably be a breaking change for CRAN
add the chunk option cache.comments; closes #718
roxygenize
bump version