#276941:

Switched from {user}->data back to og_uid_global for storing autosubscription options. Introduced hook_user.

Added an og_notifications table and migrated og_uid_global data into it.

Removed og_uid_global and vestigial og_uid_global code from og.install; moved the rest to og_notifications.

Accidentally changed the behaviour of the administrator-set default autosubscribe option. However, this might be for the better. Now, changes to the site-wide option propagate to any users who haven't overridden the option for their own accounts.

Worked around an expensive user_load call in the upgrade function. Haven't noticed any issues as of yet.

Added code to migrate the og_notification variable.

Added missing variable_del calls to hook_uninstall.

Removed variable og_omitted_email_node_types from og.install - does not appear to be required any longer.