Add linkify to the default template namespace.

tornado/template.py

@@ -119,6 +119,7 @@ class Template(object):
             "url_escape": escape.url_escape,
             "json_encode": escape.json_encode,
             "squeeze": escape.squeeze,
+            "linkify": escape.linkify,
             "datetime": datetime,
         }
         namespace.update(kwargs)

website/templates/documentation.txt

@@ -270,6 +270,7 @@ not present).
  * `url_escape`: alias for `tornado.escape.url_escape`
  * `json_encode`: alias for `tornado.escape.json_encode`
  * `squeeze`: alias for `tornado.escape.squeeze`
+ * `linkify`: alias for `tornado.escape.linkify`
  * `datetime`: the Python `datetime` module
  * `handler`: the current `RequestHandler` object
  * `request`: alias for `handler.request`