User privileges persisted after user deletion

When a user is deleted all her privileges should be deleted as well.

STEPS:
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• as 'admin' on 'quickstart'
• click the Admin cog icon
• click if needed on the word Control Panel in the upper screen breadcrumb
• click Users
• click Create user
• enter the credentials (say name:test, pwd:test)
• click the Create button
• click the new user's name
• click set group memberships
• chose every possible membership and click Add membership (there shoud be four items)
• click again Control Panel on the breadcrumb
• then click User
• then click the user's name (say ' test')
• click delete user

EXP: not only should the user be removed (OK) but the associations made between user and group as well.

ACT: see attached screenshot showing the name of the user 'test' still associated with every group (Control Panel > Groups).

The risk is that a username that has been delted cannot be reused without automatically granting all privileges of the previous to the new user. Just because two usernames are the same does not mean they have equal privileges.