Use a different module for doing nice timestamps

There is a bug in Babel[1] which means that it throws an exception if
it can’t find the locale it wants to use.

This is not a problem when developing locally, because OS X comes with
lots of locales. The AWS machines, however, only have one locale, which
is not the one that Babel is looking for. Hence the ‘Activity’ page
doesn’t work.

This commit changes to using Humanize[2] instead, which is much less
vast and hopefully less hungry in its requirements.

That’s a morning we won’t get back…

1. https://github.com/python-babel/babel/issues/137
2. https://pypi.python.org/pypi/humanize

app/templates/views/notifications.html

@@ -93,10 +93,10 @@
       </p>
     {% endcall %}
 
-    {{ text_field(item.status|title) }}
+    {{ text_field(item.status|capitalize) }}
 
     {% call field(align='right') %}
-      {{ item.created_at|format_delta }}
+      {{ item.created_at|format_delta|capitalize }}
     {% endcall %}
   {% endcall %}