GUAC-1213: Document and store user timezone such that it is used for all date/time comparisons.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-mysql/schema/001-create-schema.sql

@@ -86,12 +86,14 @@ CREATE TABLE `guacamole_user` (
   -- Time-based access restriction
   `access_window_start`    TIME,
   `access_window_end`      TIME,
-  `access_window_timezone` VARCHAR(64),
 
   -- Date-based access restriction
   `valid_from`  DATE,
   `valid_until` DATE,
 
+  -- Timezone used for all date/time comparisons and interpretation
+  `timezone` VARCHAR(64),
+
   PRIMARY KEY (`user_id`),
   UNIQUE KEY `username` (`username`)