Massive refactoring of all code + audio skeleton.

This should make it easier to find files and (in the future) split things
up into separate libraries.
It also changes around emulator initialization to make it a little more
difficult to do things out of order and a little more sensible as to when
real init work happens.
Also adding a skeleton audio system/driver and reworking CPU register
access to be more extensible.

src/xenia/gpu/d3d11/sources.gypi

@@ -1,9 +1,9 @@
 # Copyright 2013 Ben Vanik. All Rights Reserved.
 {
   'sources': [
-    'd3d11-private.h',
-    'd3d11.cc',
-    'd3d11.h',
+    'd3d11_gpu-private.h',
+    'd3d11_gpu.cc',
+    'd3d11_gpu.h',
     'd3d11_graphics_driver.cc',
     'd3d11_graphics_driver.h',
     'd3d11_graphics_system.cc',