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/kernel/util/export_table_pre.inc

@@ -14,7 +14,7 @@
  * // Build the export table used for resolution.
  * #include <xenia/kernel/util/export_table_pre.inc>
  * static KernelExport my_module_export_table[] = {
- *   #include <xenia/kernel/modules/my_module/my_module_table.inc>
+ *   #include <xenia/kernel/my_module/my_module_table.inc>
  * };
  * #include <xenia/kernel/util/export_table_post.inc>
  * export_resolver_->RegisterTable(

src/xenia/kernel/util/ordinal_table_pre.inc

@@ -15,7 +15,7 @@
  * #include <xenia/kernel/util/ordinal_table_pre.inc>
  * namespace ordinals {
  * enum {
- *   #include <xenia/kernel/modules/my_module/my_module_table.inc>
+ *   #include <xenia/kernel/my_module/my_module_table.inc>
  * };
  * }  // namespace ordinals
  * #include <xenia/kernel/util/ordinal_table_post.inc>