Cleanup xash3d_types.h from engine-specific macros and types

engine/client/client.h

@@ -1119,6 +1119,7 @@ void Con_PageUp( int lines );
 //
 // s_main.c
 //
+typedef int sound_t;
 void S_StreamAviSamples( void *Avi, int entnum, float fvol, float attn, float synctime );
 void S_StartBackgroundTrack( const char *intro, const char *loop, int position, qboolean fullpath );
 void S_StopBackgroundTrack( void );