cleanup for the appversions page

fixes bug 588120, 588144, 588141

apps/applications/templates/applications/appversions.html

@@ -8,7 +8,7 @@
 {% endblock %}
 
 {% block content %}
-<h1>{{ _('Valid Application Versions') }}</h1>
+<h2>{{ _('Valid Application Versions') }}</h2>
 <p>{% trans %}
 Add-ons submitted to Mozilla Add-ons must have an install.rdf file with at least
 one of the below applications supported. Only the versions listed below are
@@ -28,4 +28,10 @@ <h3>
 </div>
 {% endfor %}
 
+<p>{% trans url=_('http://developer.mozilla.org/en/docs/Install_Manifests') %}
+If your supported application does not require an install.rdf file, you still
+must include one with the required properties as specified
+<a href="{{ url }}">here</a>.</a>
+{% endtrans %}</p>
+
 {% endblock %}

apps/applications/views.py

@@ -5,7 +5,7 @@
 from tower import ugettext as _
 
 import amo
-from amo.helpers import url
+from amo.helpers import url, absolutify
 from .models import AppVersion
 
 
@@ -36,7 +36,7 @@ def title(self):
         return _('Application Versions')
 
     def link(self):
-        return url('apps.versions.rss')
+        return absolutify(url('apps.versions'))
 
     def description(self):
         return _('Acceptable versions for all applications on AMO.')