Create nicer Rmarkdown output

[EeethB]

When an initial graph, updated graph, or graph report is returned at the end of an Rmd chunk, it prints like it does at the console, but with #> before it. And this is sort of fine, but it's not the nicest looking. I'd like to be able to display these in a nicer way, perhaps with knitr::kable() or something

[EeethB]

knit_print() is what should be used for this, related to #27