remove chunk hyperlink from notebook progress widget

Merge pull request rstudio#697 from rstudio/feature/notebook-rmarkdow…

…n-port

use html_notebook from dev version of rmarkdown

Merge pull request rstudio#697 from rstudio/feature/notebook-rmarkdow…

…n-port

use html_notebook from dev version of rmarkdown

avoid popup overflowing bottom of page

Merge pull request rstudio#692 from rstudio/bugfix/profiler-allow-split

allow users to programmatically overwrite profiler split default

don't display mnenomics in 'edit commands disabled' dialog

handle interruption of chuck batch execution when R is not busy

handle interruption of chuck batch execution when R is not busy

handle interruption of chuck batch execution when R is not busy

more aggressive chunk output cleanup when chunk delimiters invalidated