Missing whitespace formatting for pre elements in ePub documents

The ePub version of documentation doesn't contain any whitespace formatting for pre elements, which by default don't apply any line wrapping. This results in code snippets overflow out of the screen on a ebook reader. The only way to display full snippet is to decrease font size and change page orientation to landscape.

To remedy this a single rule needs to be added to epub.css file to apply wrapping:

pre {
  white-space: pre-wrap;
}

The XSLT used to produce the ePub version of docs needs to be adjusted to incorporate that formatting.