Handle mustache l10n

[fiddur]

The way diversity.json is formed, po-files could exist in any structure.

Using PHP gettext requires a specific dir-structure. Use other lib or copy files in tmp somehow?

[fiddur]

This is the earlier try that made me realise the problems of dir structure:

/// @todo Handle gettext
//if (isset($this->spec->i18n->$language->backend)) {
//  $po_dir = $this->getAssetUrl() .
//    substr($this->spec->i18n->$language->backend, 0, -strlen($language . '.po'));
//  $gettext_domain = 'apa';//$this->name . ':' . $this->version;
//  bindtextdomain($gettext_domain, $this->base_dir . 'locale');
//  //trigger_error("Set $gettext_domain to " . $this->base_dir . 'locale');
//
//  $template_data->gettext = function($text, $mustache) use ($gettext_domain) {
//    //trigger_error("domain: '$gettext_domain': " . dgettext($gettext_domain, trim($text)));
//    return $mustache->render(dgettext($gettext_domain, trim($text)));
//  };
//}