increase system-wide filename limit to 255

. move mfs-specific struct, constants to mfs/, so
	  mfs-specific, on-disk format structs and consts are
	  fully isolated from generic structs and functions
	. removes de and readfs utils

include/sys/Makefile

@@ -2,7 +2,7 @@
 
 INCSDIR=        /usr/include.ack/sys
 
-INCS=	asynchio.h dir.h file.h  \
+INCS=	asynchio.h file.h  \
 	ioctl.h ipc.h jmp_buf.h kbdio.h mman.h \
 	mount.h mtio.h param.h ptrace.h queue.h resource.h \
 	select.h sem.h shm.h sigcontext.h signal.h socket.h \

include/sys/dir.h

@@ -1,11 +0,0 @@
-/*
- * this files resolves conflicts between the file of the host system and
- * the minix specific one. This file is included directly only on Minix
- * and it is an error to do so on any other system
- */
-
-#if !defined(_MINIX) && !defined(__minix) && !defined(__ACK__)
-#error "Including Minix specific file in program targeted for other system"
-#else
-#include <minix/dir.h>
-#endif