A nicer look for the documents listing

This change includes a filthy hack around how Django handles
change_list_results.html -- I'm not thrilled with it, but it's as
elegant as I could come up with.  I'm happy to field alternative ideas.
More details can be found in `documents/templatetags/hacks.py`

Specifically, this merge includes a significant facelift to the
documents listing page, moving away from the tabular layout and toward a
tileset look.  I tried fiddling with the colours, but I just don't have
any skills in that area, so we're all stuck with Django'd default
colours until someone with an eye for colour can submit a better CSS.

requirements.txt

@@ -1,18 +1,18 @@
-Django==1.10.4
+Django==1.10.5
 Pillow>=3.1.1
-django-crispy-forms>=1.6.0
-django-extensions>=1.6.1
+django-crispy-forms>=1.6.1
+django-extensions>=1.7.6
 django-filter>=1.0
-djangorestframework>=3.4.4
+django-flat-responsive>=1.2.0
+djangorestframework>=3.5.3
 filemagic>=1.6
-langdetect>=1.0.5
-pyocr>=0.3.1
-python-dateutil>=2.4.2
-python-dotenv>=0.3.0
-python-gnupg>=0.3.8
-pytz>=2015.7
+langdetect>=1.0.7
+pyocr>=0.4.6
+python-dateutil>=2.6.0
+python-dotenv>=0.6.2
+python-gnupg>=0.3.9
+pytz>=2016.10
 gunicorn==19.6.0
-django-flat-responsive==1.2.0
 
 # For the tests
 pytest