Refactoring
Fix error rendering in Foundation
Tidying up

Removed some cruft from templates and added a few useful new globals to
the template namespace (webhelpers, markup, html, etc.)
Added admin templates & views for comic pages
Start work on adding filenames to database

Need to break the link between the filenames for comic pages and the
primary key of a comic page otherwise changes to the key (on deletion of
pages for example) will lead to incorrect filenames on disk. Instead
page files should have a persistent filename stored in the database, and
some extra magic will be required to keep the filenames coherent with
the state on disk