Confusions and incompatibilities when migrating to Django 1.10
meant conslidating the places we get CSS files and site media such as gifs 
for page annoations.

Situation as of 17/6/2020:
We have 3 folders for CSS files in 3 very different places:
1 in expoweb repo
1 in troggle repo
1 not in either repo but intimately needed by troggle

These are (in /home/expo/ ):
1. expoweb/css/ (used by the handbook)
2. troggle/media/css/ (used by troggle pages)
3. static/admin/css (used by django control panel and django plugins)

1. expoweb/css/        flatviews.flatpage      - the url is /css/main2.css
2. troggle/media/css/  MEDIA_ROOT, MEDIA_URL   - the url is /site_media/css/main3.css
3. static/admin/css    STATIC_ROOT, STATIC_URL - the url is /static/admin/css/base.css

After installing Django, weneed to manually copy its CSS etc. files from,
e.g. /usr/lib/python3.7/site-packages/django/contrib/admin/static/admin/css
to
/static/admin/css/base.css
if there are changes. But our old set of gifs is probably better.

from django.contrib.staticfiles import views as staticviews
from flatpages import views as flatviews

1.    url(r'^(.*)$', flatviews.flatpage, name="flatpage"),

2.    url(r'^site_media/(?P<path>.*)$', staticviews.serve,  {'document_root': settings.MEDIA_ROOT, 
            'show_indexes': True}),
3.    url(r'^static/(?P<path>.*)$',     staticviews.serve,  {'document_root': settings.STATIC_ROOT,
            'show_indexes': True}),

Also (for development only):
    url(r'^expofiles/(?P<path>.*)$',  staticviews.serve,  {'document_root': settings.EXPOFILES, 
            'show_indexes': True}),
