movies: Move wavAudio.h include from wavAudioCursor.h to .cxx, per rdb's suggestion.

panda/src/movies/wavAudioCursor.cxx

@@ -15,6 +15,7 @@
 #include "wavAudioCursor.h"
 #include "config_movies.h"
 #include "virtualFileSystem.h"
+#include "wavAudio.h"
 
 // Tables for decompressing mu-law and A-law wav files.
 static PN_int16 mulaw_table[256] = {

panda/src/movies/wavAudioCursor.h

@@ -19,7 +19,7 @@
 #include "movieAudioCursor.h"
 #include "streamReader.h"
 
-#include "wavAudio.h"
+class WavAudio;
 
 ////////////////////////////////////////////////////////////////////
 //       Class : WavAudioCursor