More/better translation.

- Try to preserve some translations (somehow).
- Mark "Tagged with" again for translation.
- Do not translate the empty string

mediagoblin/user_pages/forms.py

@@ -21,7 +21,7 @@ from mediagoblin.tools.translate import fake_ugettext_passthrough as _
 
 class MediaCommentForm(wtforms.Form):
     comment_content = wtforms.TextAreaField(
-        _(''),
+        '',
         [wtforms.validators.Required()])