Revealed a pretty interesting bug which basically means that I need to do some
work on per-CPU threads earlier than expected. Other than that, kernel is
moving along well. Integrated the new callback system into the kernel proper.
Still need to replace the current Timer Stream infrastructure with the new
framework, but it's viable as tests have shown so far.

I believe that this is also the patch in which I fully introduced asynchonous
process spawning callbacks (working well also).

* New gitignore rules to ensure that new Makefiles aren't ignored.
* Processes and threads now store complete IDs in their structures, and callers
  needing to extract portions of a full thread ID should use the PROCID_*
  macros to do so.
* Created a little utility function enqueueCallback() that will reduce code
  duplication in the kernel for enqueueing callback messages.
* ProcessStreamC::commonEntry now queues callbacks for new process creation
  calls.