locally defined K&R prototypes in .c files; use appropriate casts for
pointer types now that types for arguments are available at compile time.
This ensures that compilers with multiple incompatible calling conventions
can select the correct calling convention for external functions.
Sponsored by: DARPA, AFRL
MFC after: 1 week
o main returns int not void
o use return 0 at end of main when needed
o use braces to avoid potentially ambiguous else
o don't default to type int (and also remove a useless register
modifier).
Reviewed by: obrien and chuckr
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.
