Move checkout status widget code to a separate file

apps/checkouts/widgets.py

@@ -0,0 +1,17 @@
+from __future__ import absolute_import
+
+from django.utils.translation import ugettext_lazy as _
+from django.utils.safestring import mark_safe
+from django.conf import settings
+
+from .literals import STATE_CHECKED_OUT, STATE_CHECKED_IN, STATE_ICONS, STATE_LABELS
+
+
+def checkout_widget(document):
+    checkout_state = document.checkout_state()
+
+    widget = (u'<img style="vertical-align: middle;" src="%simages/icons/%s" />' % (settings.STATIC_URL, STATE_ICONS[checkout_state]))
+    return _(u'Document status: %(widget)s %(text)s') % {
+        'widget': mark_safe(widget),
+        'text': STATE_LABELS[checkout_state]
+    }