This runs xml2rfc on all RFCs with a .xml file to generate text RFC output.

New text RFC output is compared with the original and any differences are saved in the text_results.

New HTML RFC output is compared with the original and any differences are saved in the html_results.

In html_results, *.diff.txt files have plain diff of the HTML, *.vdiff.html files have visual diff from Selenium.

The xml2rfc.txt file inside result directories contains xml2rfc and other Python libraries' version information.