TODO:

* Duplication of first maintainer when editing to add a second?
* Document macros for URL fields

Later:
* Breadcrumbs / fix tab navigation?
* Ability for reviewers to comment before publishing a layer?
* Add link to the all layers and all recipes tables from the layer details page?
* Prevent SMTP failures from breaking submission process
* All-branch search/results so you can see version availability of recipes in all branches at once?
* Rawrecipes branch support
* Display no-results found message when search does not return any results (all tables)
* Change behaviour of filter menus to stay open so that you can check / uncheck multiple items
* Show layer type in layer detail?
* Usage links in list page?
* Subdirs in list page?
* Avoid page content changing size depending on whether scrollbar is there or not?
* Query backend service? i.e. special URL to query information for external apps/scripts
* Add comparison to duplicates page
* Dynamic loading/filtering for recipes list
* Some way to notify the user when they search for something that has been renamed / replaced / deprecated?
* Create simple script to check for unlisted layer subdirectories in all repos
* Are we going to need some way of indicating forks of another layer? (would rather avoid having forks altogether...)
* Auto-detect more values from github pages?
* Ability for submitters to get email notification about publication?