changed create badge url to /new-badge
Added basic awards_by_user url, view and template.
Getting SECRET_KEY from env variable DJANGO_SECRET_KEY
Added award_detail url, view and template
moved currently unused templates to unused folder
minor cleanups
Fixed get_absolute_url for Award model; now works (though I had to disable the permalink decorator - this will need to be re-thought for multi-domain sites anyway)
Added 'AwardsByBadge' view

- Added 'AwardsByBadge' to views.py, modelled symmetrically around
'AwardsByUser'.
- Added url for 'AwardsByBadge' to urls.py
- Added some required fields for the 'User' object in models.py, in a
comment (fields used by AwardsByBadge templates)
- Added 'awards_by_badge.html' template
- Added 'awards_as_users_list.html' template (to be included in
'awards_by_badge')
- Added comments throughout project to clarify some doc discrepancies
- Deleted 'awards_by_badge' from 'unused' (since it's now effectively
used, though restructured)

Note there is commented-out code in the 'awards_by_badge.html' template,
regarding the 'extrahead' block and inclusion of the 'badge_full.html'
template (which is yet unfinished)