Update rust-core. Revised runtime instructions.
Buddy: optimize
ARM: update
Kernel: zero_alloc, realloc_raw
ARM: Int enum

Conflicts:
	arch/arm/drivers/mod.rs
Refactor BuddyAlloc -> VirtAlloc
Alloc: element size for an allocator (power of 2)
Alloc: physical frames
mmu: reorganize. Nicer implementations.
Support breakpoints. Exception exit summary
Merge pull request #2 from pczarn/ironkernel

MM and interrupt improvements. (last 2 weeks)