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/apu/sources.gypi

@@ -0,0 +1,23 @@
+# Copyright 2013 Ben Vanik. All Rights Reserved.
+{
+  'sources': [
+    'apu-private.h',
+    'apu.cc',
+    'apu.h',
+    'audio_driver.cc',
+    'audio_driver.h',
+    'audio_system.cc',
+    'audio_system.h',
+  ],
+
+  'includes': [
+    'nop/sources.gypi',
+  ],
+
+  'conditions': [
+    ['OS == "win"', {
+      'includes': [
+      ],
+    }],
+  ],
+}