German translation, from Alexander Hesse
Ensure that users aren't really deleted.
Security fix for rails.
Set the i18n validation config to silence the warning.

Thanks to http://stackoverflow.com/questions/20361428/rails-i18n-validation-deprecation-warning
for the great explanation
Don't count deleted users as active.
Ensure profile is cleared, name changed and locations removed when deleting users.
Ensure deleted users are removed from groups and unsubscribed from threads.
Remove unecessary context.
Ensure correct behaviours when cancelling your account.
Merge branch 'deleting-users' into staging
scope the column names to avoid ambiguous column errors.
Add joining instructions to new membership requests page. Closes #239 Refs #271
Proper label for group membership requests. Refs #271.
Use button i18n in test.
Use FactoryGirl to create test objects rather than doing so directly.

This avoids problems with attr_accessible being introduced.
Add message text to group membership requests.
Allow users to specify a message when asking to join.
Show joining message in notifications.
Show membership request messages on the review page and indicate they exist on the overview.
Use factorygirl to avoid mass assignment errors.