Changed parity & stop bits to an enum (you can now pass in 1.5). I've updated the uarts that were testing for 1.5 stop bits to pass that in, but there are probably others & 1.5 stop bits is converted to 2 by diserial. However the 68681 requires stop bits to be specified in clocks, so this will change in the future. Replaced synchronous flag with start bit count, as some uarts can use a start bit in synchronous mode & that whether there is a start bit is all the flag is currently controlling. Updated rs232 terminal to allow startbits, stop bits 1.5 to be specified (although that is currently not supported by diserial) and individual transmit and receive baud rates. [smf]