Move sound id declarations to cpp file to reduce redundant linker symbols.

Cuts size of object files dramatically, often 100KB apiece.

indra/llmessage/CMakeLists.txt

@@ -100,6 +100,7 @@ set(llmessage_SOURCE_FILES
     patch_code.cpp
     patch_dct.cpp
     patch_idct.cpp
+    sound_ids.cpp
     )
 
 set(llmessage_HEADER_FILES