Insert New Class (a2BusNew under BusItem)

1. edit/create the file: dir/svr/bbkins.met, add the fellowing line:
   insert a2BusNew under BusItem;
2. edit the file: dir/svr/mti.prd, add the fellowing as first line:
   include "bbkins.met"
3. attach attribute and(or) message to a2BusNew class, create new file at dir/src/a2BusNew.met, adding
   the fellowing line:
   attach message IncrementRevision to a2BusNew in server bbksvr;
   a2BusNew.Revision = "-";
4. create new file at dir/src/a2BusNew.mth, adding the override IncrementRevision message code at this
   file;
5. modify the dir/src/srcdcusmk.def, be sure to include files "a2BusNew.met" and "a2BusNew.mth"
6. rebuild all.