Hardware: separate out CPU values into CPU module

* CPU functions now exist in Hardware::CPU
* Added compatibility functions in compat/hardware_compat.rb
* Names are less specific to Mac hardware, e.g. CPU.family instead of
  Hardware.intel_family
* Hardware::CPU.family works for both Intel and PowerPC
* New helper methods on CPU, like .sse4? and .altivec?

Signed-off-by: Misty De Meo <mistydemeo@gmail.com>