Revised MySQL schema
Error catching if a user isn't returned for some reason
Revised entity reference length
New table for session handling
Better pass by reference handling for unset properties
Minor syntax change
Removing extraneous gatekeeper call
Unique key schema
MySQL session handling, object storage & retrieval
Improved configuration retrieval
Restored compatibility with MongoDB back-end for site config
Moving getAndFlushMessages to the top of the page
Idno => Known
Array access interface for entities
idno => known
Extra metadata deletion code and database default values
Vain attempts to fix #291
Removing debugging message
Messages are now unstick; fixes #291

Additionally, sessions are closed before page output. All is well with
the world. Cats and dogs no longer living together. Mass hysteria
averted.
Removing debugging messages for MySQL