* UserSettings: crashed if overwrite an existing key with primitive value by same key with complex value. Also reduced number of calls to user.get_setting()
* Updated tests
(cherry picked from commit b75b53d)
That should fix user settings across multiple SessionUser wrappers. User settings were
previously only copied upon initialization of the SessionUser, with no update later on,
leading to them becoming out of sync with the underlying User instance.
This commit changes SessionUser to delegate method and attribute access for anything
but its own members to delegate to the wrapped User instance instead.
