VoIP: Save own voice when recording a demo.

We fake a server packet and write it directly to the demo file at the point
 where we'd transmit to the server. This is a little nasty, but it seems to
 be the most reasonable solution.

code/client/client.h

@@ -615,3 +615,9 @@ void CL_WriteAVIVideoFrame( const byte *imageBuffer, int size );
 void CL_WriteAVIAudioFrame( const byte *pcmBuffer, int size );
 qboolean CL_CloseAVI( void );
 qboolean CL_VideoRecording( void );
+
+//
+// cl_main.c
+//
+void CL_WriteDemoMessage ( msg_t *msg, int headerBytes );
+