[1.5.x] Add release date to 1.5 release notes.
[1.5.x] Add release date to 1.5 release notes.

bliti/django-nonrel-1.5,imtapps/django-imt-fork,ccn-2m/django,alx-eu/django,ccn-2m/django,imtapps/django-imt-fork,hasadna/django,ccn-2m/django,alx-eu/django,imtapps/django-imt-fork,alx-eu/django,bliti/django-nonrel-1.5,alx-eu/django,hasadna/django,hasadna/django,bliti/django-nonrel-1.5,ccn-2m/django