[Rd] Double HTML encoding in R Bug Tracking Submission form (PR#11517)

[mwtoews at sfu.ca]

The "New Bug Report" form available from http://bugs.r-project.org/ 
appears to double encode the HTML of the "body" text area of the form.

This behaviour can be seen in submission ID # 11515, where (as an 
example) "Δ" is converted to "Δ" in the browser view or 
"Δ" in the HTML source code. Conversion to "Δ" in the HTML 
source is sufficient to render "Δ" in the browser output.