Fixed github issue #8. Submitting no values via POST to play.php redirects to index.php. Also cannot replicate issue where the GO button allows you to do this before the pages have loaded in the text boxes. So the redirect will only take effect when a user goes directly to the play.php page.
Added meta tag to apply content type and UTF-8 charset to both play and index .php. This solves github issue #11
Fixed issue #13. Ignore all links to wiktionary.org