Supports concordances in 'R Markdown' documents. This currently allows the original source location in the '.Rmd' file of errors detected by 'HTML tidy' to be found more easily, and potentially allows forward and reverse search in 'HTML' and 'LaTeX' documents produced from 'R Markdown'. The 'LaTeX' support has been included in the most recent development version of the 'patchDVI' package.
