8 commits: unique models.*.slug, show photo exif info, cleanups and refactoring
Merge branch 'dev'

* dev:
  New templatetag: photo_title (with default for photos without title)
  contact message update
  Cleanup: extra template tags formatting
  Removed test.jpeg
  Favicon
  Cleanup: remove django-adminfiles dependency
  index page: see featured only
  Show photo exif shot info via extra templatetag on photo page
  Refactored Photo model signal connection to avoid receiving signals twice. Added post_save handler
  Added unique to slug field in models, contact message update
Merge branch 'dev'

* dev:
  Photogrid: fade in photos loaded via ajax
  load more grid-pages: define photos per page in settings; scroll spy to auto-reload
Merge branch 'dev'

* dev:
  Fix: photo mover
Merge branch 'dev'

* dev:
  update initial grid size to 11 photos, 6 per extra page, and reload earlier
Release Merge: photo-flow

* dev:
  added photoflow-wrapper
  cleanup
  photo flow captions (on hover)
  quick layout test with /flow/?l=1,2
  Flow Ajax More
  PhotoFlow Manager
  responsive images in photoflow; added adminvalues model
  Simplified adding flow-layouts
  moved the photoflow helpers from templatetags/extras.py to tools/photoflow.py
  Flow Renderer (auto-builds columns based on schema definitions)
  photo flow starts looking good
  very simple working div system (+frames)
  photoflow with div (not yet working)
  Start photoflow
  css improvements: font-weight:300; on larger texts
  Photo title: 'Go Fullscreen'
Release merge: PhotoFlow as index, AdminValue updates, Minor bugfix in css

* dev:
  AdminValue pretty admin
  Added adminvalues.py with keys. Flowmanager now uses PHOTOFLOW_LAYOUTS for default and PHOTOFLOW_LAYOUTS_TEST for /flow/
  Switch front page to flow. Minor refactorings
  phtoflow bugfix: title inside frame
Django Email sending, AdminValues, bgjobs, more caching, css+js minification

* all commit messages:
  small comment update in bgjobs
  settings log update
  replaced tools.sendmail with django email sending
  Set file-loglevel to info
  adminx index page 2 cols in grid
  Added enabled field to AdminValue model
  AdminValues doc update
  Readme update
  RebuildFlowFrontpage bgtask
  mainapp/bgjobs.py: Background Jobs with Threading
  Cache ajax page loads
  adminvalues: override settings with the admin interface
  Start AdminValues: helper to override settings/defaults with AdminValues
  admin interface updates; bugfix in models.Photo.post_delete (check whether file exists before removing)
  Templates use minified js + css files
  build.py minify css + js
  nginx config tweak: Cache-Control public for images
  Minor fix: in photoflow set header-width margin -13 to compensate for flow right margin
  Bugfix: photoflow ajax load more with >1 block works now. Adjusted flow-initial to 3 blocks, perpage to 2 blocks to reduce loadings
Redis auth bugfix. Some refactorings and disable logged in user middleware caching (for admin interface)

* dev:
  Refactored adminvalues to make them even easier to access
  fabfile bugfix: upload settings before manage.py migrate. AdminValue admin interfae. Enable settings.CACHE_MIDDLEWARE_ANONYMOUS_ONLY
Photo 404. Proper 404 page