create new session on class call, there is no need to delay that at all
new option to auto write close a session
session_id and session_name are stored as class vars
deprecate the __set/__get part because we do not want to set via ->session_var_name
but use the set()/get() methods.
They have been renamed from setS/getS... to set/get alone
DB Class throws Exception if on init it fails to connect to the DB,
will not throw Exception if failed connection during execution but
will do the normal retry and soft failure run
DB\ArrayIO will throw Exception on missing table array and table name
All Exceptions have a code set
