* Added a 'STACK_SCHED_CODES' table to the database.
* Dropped the 'STACK_LINES.SCHED_CODES' field from the database.
* Incremented the database version to 308.
* Renamed the 'SchedCartList' class to 'RDSchedCartList' and
refactored it to be idiomatic Qt.
* Renamed the 'SchedRulesList' class to 'RDSchedRulesList'.