o Use new-style prototypes exclusively rather than the old foo() style.
o Use new-style function definitions.
o remove register
o make functions passed to signal have the right signature.
o do minor const poisoning.
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.
