Bugfix: Show stats for projects with dots in its code

The JavaScript code was replacing some characters in the project code (see
https://github.com/translate/pootle/blob/fc615e8e/pootle/static/js/stats.js#L132)
for retrieving the HTML nodes to set the counts, but the HTML output by
Python didn't had those characters replaced, and thus it was impossible
to locate such nodes.

Fixes #3246