Activity log widget for sidebar

[giplt]

Create a view on activity across all of the site, engaging users and visitor alike by offering a view on the involvement of others

• set up log rotating table for digest
• create read/write calls for log table
• create menu widget
• add digest option in personal settings
• add cron mechanism for differentiated digest delivery

Elaborate on (user defined) digest mechanism: stats vs log lines: define logtypes:

• site settings
• visitor stats
• content mutations
  Different tables for different logtypes
  Site-log vs content log
  Prevent flushing one log type by others...