WARNS6 cleanup (1803 warnings).
ANSI function declarations.
Staticize functions.
Rename local variables that shadow globals.
Use string functions from libc instead of creating our own.
Remove void casts for unchecked function returns.
Spell parameter correctly.
Don't try to return a value from void functions.
Remove compat library requirement (gtty -> ioctl).
Add new function "dowarp" that calls warp() from play.c. (Taken from
NetBSD).
Change chars that are used for numeric values to shorts so they can be
properly used as array indexes.