Changes to sample programs

Two C language programs from the IIOP Bank Account sample application (transaction BNKQ) have been modified to show how a channel can be passed on EXEC CICS® LINK and RETURN commands. DFH$IIBQ, the top-level program, and DFH$IICC, the program it links to, have been modified to use the channel/container model rather than the COMMAREA model. Comments in the code show the changes that have been made.