Jr. instead of Jr
cosmetic
only need to call knit() once
quit without saving
use -h and -n for --help and --no-convert respectively
add a new option -o to bin/knit; closes #525

also need to allow output=NA in knit(), and add an 'output' argument to knit2html()
emphasize 'output' is for knit() only; also add a note for knit2pdf() (#500)
roxygenize
cosmetic (use single quotes)
make sure knit_theme$set() really finds the css file (as @richierocks suggested); closes #522
need to merge low-level changes in the test; see hadley/evaluate#31
closes #519: include=FALSE means do not include code in purl()
bump version