Remove unused code and classes.
Clean up code to remove all named constant from them and throw
deprecation alerts if used.
Add basic psalm setup in root folder and remove from www folder
All static Session:: calls (except for checking valid session name) are
converted to object type. This Object is passed on to Login, Admin
Backend and any other class that needs basic session checking
Add a write close session call to end a session for AJAX calls
Add error strings to session start method
Add check call for session names that they are valid
