Now that the number of clist consumers have dropped massively, trim down
the code to prevent useless waste of space.

• Remove support for quote bits. There is not a single driver that needs these bits anymore. This means putc() now accepts a char instead of an int.

• Remove the unneeded catq() and nextc() routines. They were only used by the old TTY layer.

• Convert the clist code to use ANSI C prototypes.