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/cpu/sdb/xex_symbol_database.h

@@ -23,7 +23,7 @@ namespace sdb {
 class XexSymbolDatabase : public SymbolDatabase {
 public:
   XexSymbolDatabase(xe_memory_ref memory,
-                    kernel::ExportResolver* export_resolver,
+                    ExportResolver* export_resolver,
                     SymbolTable* sym_table, xe_xex2_ref xex);
   virtual ~XexSymbolDatabase();