Added database, API and GPX status to capabilities.
Localisation updates from http://translatewiki.net.
Correct next/previous links on diary list page
Fix next/previous links on diary pages properly
Update Potlatch 2 to 2.3-584-g996bb4d build
Localisation updates from http://translatewiki.net.
Diary cleanup

This commit includes a few basic changes to make the user diaries
friendlier and easier to read. I adjusted the text styles and added
a maximum width, to keep the line length under control.
Add iD editor

iD sources live in vendor/assets/iD, and are managed with
vendorer, using the "rewrite" functionality to replace relative
paths in the CSS with <%= asset_path(…) %> directives.

To avoid needing to namespace all of its CSS classes, iD
is embedded via an iframe.

To setup, edit application.yml to include an `id_key` key.
(It can use the same consumer key as P2 if you like.)