Fix object_history template for Django 1.7

This fixes:

    `NoReverseMatch at /admin/app/model/15/history/`

     Reverse for 'app_list' with arguments '()' and keyword arguments
     '{u'app_label': ''}' not found. 1 pattern(s) tried:
     [u'admin/(?P<app_label>movies|sites|auth|redisboard|taggit)/$']

It also merges other changes in this section from the 1.7 template.