New UTCB implementation almost working.

- KIP's pointer to UTCB seems to work with existing l4lib ipc functions.
- Works up to clone()
- In clone we mmap() the same UTCB on each new thread - excessive.
- Generally during page fault handling, cloned threads may fault on the same page
  multiple times even though a single handling would be enough for all of them.
  Need to detect and handle this.

src/api/kip.c

@@ -12,7 +12,6 @@
 #include INC_GLUE(memlayout.h)
 #include INC_ARCH(bootdesc.h)
 
-/* FIXME: Change the unit name */
 __attribute__ ((section(".data.kip"))) struct kip kip;
 
 /* Error-checked kernel data request call */