This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
TS_CAR_OFLOW, TS_CTS_OFLOW, TS_DSR_OFLOW and TS_ZOMBIE.
Document old tty states TS_ASLEEP and TS_TTSTOP more completely.
Document old tty states TS_ASYNC and TS_TBLOCK.
Document not so old tty states TS_CAN_BYPASS_L_RINT and TS_SNOOP.
Don't document nonexistent state TS_HUPCL.
Document the current line disciplines instead of prehistoric ones.