Fix printing to screen
Fix the IDT and IRQ setups by copying more from JamesM's files, and also further increase debugging when an unhandled interrupt occurs. Move IRQ setup routines out of init_idt (soon to be added to main)
Fix build (was creating stupid files)
Implement an internal timer, using the PIT. All fully documented. Now we can see as seconds pass! (As part of this, the IRQ is setup properly again)