Explain how to load data for testing

This is a fairly common query, and not too complicated where the data only needs to be loaded.

Loading data then editing it is more complex, and not covered here.
Ban usernames which match special URLs

Trac #5236
Update to rails 4.1.6
Test that reserved usernames are not allowed
Localisation updates from https://translatewiki.net.
Forward the `comment` hash parameter to iD

See https://github.com/openstreetmap/iD/commit/21da76cf8060832e36d341d9bd41dd1142810b08
Update to iD v1.6.0
Update to CPK 7.0.11 and drop monkey patch
Don't pass the hash when routing an empty search query

Fixes #793
Update Potlatch 2 to 2.3-645-g81e8bcb build
Add missing event types to note comment fixtures
Validate note comments for control characters
Add some more model tests for notes and note comments
Merge remote-tracking branch 'osmlab/iD-1.6.0'
Update Potlatch 2 to 2.3-648-g9cab056 build
Localisation updates from https://translatewiki.net.
Changeset discussions

Add support for commenting on changesets with RSS feeds and email
notification of comments to other commenters and people that have
chosen to subscribe to a changeset.
Tidy up changeset comment code
Tidy up changeset comment tests and beef them up a bit