[views] use pictogram (closes #3803725)

views.py

@@ -181,8 +181,9 @@ class RegisterLink(basecomponents.HeaderComponent):
     context = 'header-right'
 
     def render(self, w):
-        w(u'[<a class="logout" href="%s">%s</a>]' % (
-            self._cw.build_url('register'), self._cw._('i18n_register_user')))
+        self._cw.add_css('cubicweb.pictograms.css')
+        w(u'<a class="logout icon-user-add" title="%s" href="%s"></a>' % (
+                self._cw._('i18n_register_user'), self._cw.build_url('register'), ))
 
 ## urls #######################################################################