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/system/do_exit.c

@@ -28,13 +28,13 @@ message *m_ptr;			/* pointer to request message */
       exit_proc_nr = m_ptr->PR_PROC_NR;		/* get exiting process */
       if (exit_proc_nr != SELF) { 		/* PM tries to exit self */
           if (! isokprocn(exit_proc_nr)) return(EINVAL);
-          clear_proc(exit_proc_nr);		/* exit a user process */
+          clear_proc(proc_addr(exit_proc_nr));	/* exit a user process */
           return(OK);				/* report back to PM */
       }
   } 
 
   /* The PM or some other system process requested to be exited. */
-  clear_proc(m_ptr->m_source);
+  clear_proc(proc_addr(m_ptr->m_source));
   return(EDONTREPLY);
 }
 #endif /* USE_EXIT */