LPS-45230 Post-Upgrade Activities portlet doesn't show document links

Hai Yu, 

We should NEVER EVER be deleting entries from the database and recreate them in any case. There are other database entity that depends on these entries (from both portal or plugins) and by deleting the entries and recreating them. The activityId is now different and all those dependent entities are pointing to nothing. 

We should iterate all the existing entry and upgrade them using UPDATE. NOT DELETE.

Social Office's Activities are now all broken if the clients have run this upgrade, and we can never retrieve the database entries ever again.

This breaks our promises to plugins developers that their plugins should always work even after portal fixes. We should fix this soon in SP8