Various fixes and improvements.

- fixed bug that caused IDLE to panic (irq hook inconsistency);
- kprintf() now accepts multiple arguments; moved to utility.c;
- prepare_shutdown() signals system processes with SIGKSTOP;
- phys_fill() renamed to phys_memset(), argument order changed;
- kmemset() removed in favor of phys_kmemset();
- kstrncpy() removed in favor of phys_copy();
- katoi, kstrncmp replaced by normal library procedure again;
- rm_irq_handler() interface changed (simply pass hook pointer);

kernel/Makefile

@@ -14,7 +14,7 @@ CFLAGS = -I$i
 LDFLAGS = -i 
 
 HEAD =	mpx.o
-OBJS =	start.o protect.o klibc.o klib.o table.o main.o proc.o \
+OBJS =	start.o protect.o klib.o table.o main.o proc.o \
 	i8259.o exception.o system.o clock.o utility.o debug.o
 SYSTEM = system.a
 LIBS = -ltimers