some plugins need to be fixed yet: ticket, gallery, group, menu
- added current user to default models as "user"
- renamed in User: super_user -> is_super_user, env -> admin_env, pass_hash_salted -> is_pass_hash_salted
- now Users class has a WinixModel as a base class
some plugin calls have to be fixed yet
- added UserWrapper model with a pointer to User class
- removed from ItemContent: methods for accessing 'meta' and 'admin_meta', now ezc can iterate through Space classes
- fixed in env winix function: if there is "changeuser" parameter then we should only switch the user (not save anything)
- User and Group has been moved to 'models' directory
- removed UserPass struct (passwords fields were put to User struct)
not working yet, we need support for binary blobs in morm