Managed to self-destruct pager.

Issues:
- A page-faulting thread suspends if receives -1 from pager page fault ipc.
  This is fine if pager is about to delete the thread, but it is not if
  it is a buggy pager.
- Need to find a way to completely get rid of suspended pager.
- A method of deleting suspended tasks could remedy both cases above.

include/l4/macros.h

@@ -91,6 +91,8 @@ static inline int is_err(int x)
 
 #define BUG_ON(x)		{if (x) BUG();}
 
+#define WARN_ON(x)	{if (x) printk("%s, %s, %s: Warning something is off here.\n", __FILE__, __FUNCTION__, __LINE__); }
+
 #define BUG_ON_MSG(msg, x)	do {				\
 					printk(msg);		\
 					BUG_ON(x)		\