Rework of member create

Combine add/edit members

Focus login field when adding first user

Use member login as display name fallback

Track dirty forms

Add role help

Make table action links smaller

Improve 0-member case

Update read-only descriptions

Handle empty allowed_gear_sizes correctly, allow submitting update with no changes

Fix rest api membership tests to use login field
Refactor url rewrite after domain create
Fix test cases
Update error code for no changes
Merge pull request #15 from liggitt/membership_plus_console

Rework of member create