Use CreatedAtBookkeeper for albums
Order an album's images by [photographed, created] [#19]

The date an image's record was created in the catsnap database isn't
nearly as interesting as the date the image itself was created.
Test and fix json-formatting for view-album [#19]
Fix a bug in with_settings

with_settings needs to mess with argument_config, since that's the
highest-priority config. Using env vars, it's possible for a rogue
.catsnap file to override a with_settings declaration.
Display albums as a thumbnail gallery [#19]
 Merge branch 'album-gallery-view' into 'version-5'

Album Gallery View

Fixes #19