-WARNS6 cleanup (4670 warnings)

-WARNS6 cleanup (4670 warnings)
-ANSI function declarations
-Staticize functions
-Rename local variables that shadowed global declarations
-Remove an extra semicolon after an if statement in makemaze()
-Remove code that was previously commented out, or that was unused
-Use NULL for string pointers == 0 and don't redefine NULL
-Add function protoypes for all functions
-Add macros for stty and gtty that use ioctl which removes the dependency
	on libcompat.
-Add DragonFly keyword where needed
-Add new arrays (potionhide/scrollhide) to prevent modifying string
	constants, then fix problems associated with this hiding
	mechanism.  (taken from NetBSD)