Try up to 20 random ports if necessary
no need to expose the documentation to users; expose registerShinyDebugHook to R so that R CMD check does not complain

per discussion in #258, and closes #259
roxygenize
Merge pull request #262 from yihui/r-check

synchronize doc
allow a custom function for the launch.browser parameter
Merge pull request #252 from jcheng5/random-ports2

Try up to 20 random ports if necessary
roxygenize
Fix typo
Merge remote-tracking branch 'rstudio/master'
Merge branch 'master' of github.com:trestletech/shiny