Remove unused URLSong functionality

This isn't supported with the OpenAL backend, and instead of trying to make a
workaround for it, a better approach would probably be to make a FileReader
implementation that handles URLs.

src/s_sound.cpp

@@ -2596,21 +2596,8 @@ bool S_ChangeMusic (const char *musicname, int order, bool looping, bool force)
 		{
 			if ((lumpnum = Wads.CheckNumForFullName (musicname, true, ns_music)) == -1)
 			{
-				if (strstr(musicname, "://") > musicname)
-				{
-					// Looks like a URL; try it as such.
-					handle = I_RegisterURLSong(musicname);
-					if (handle == NULL)
-					{
-						Printf ("Could not open \"%s\"\n", musicname);
-						return false;
-					}
-				}
-				else
-				{
-					Printf ("Music \"%s\" not found\n", musicname);
-					return false;
-				}
+				Printf ("Music \"%s\" not found\n", musicname);
+				return false;
 			}
 			if (handle == NULL)
 			{

src/sound/i_music.cpp

@@ -558,25 +558,6 @@ MusInfo *I_RegisterCDSong (int track, int id)
 	return info;
 }
 
-//==========================================================================
-//
-//
-//
-//==========================================================================
-
-MusInfo *I_RegisterURLSong (const char *url)
-{
-	StreamSong *song;
-
-	song = new StreamSong(url);
-	if (song->IsValid())
-	{
-		return song;
-	}
-	delete song;
-	return NULL;
-}
-
 //==========================================================================
 //
 // ungzip

src/sound/i_music.h

@@ -57,7 +57,6 @@ class MusInfo;
 struct MidiDeviceSetting;
 MusInfo *I_RegisterSong (FileReader *reader, MidiDeviceSetting *device);
 MusInfo *I_RegisterCDSong (int track, int cdid = 0);
-MusInfo *I_RegisterURLSong (const char *url);
 
 // The base music class. Everything is derived from this --------------------
 

src/sound/i_musicinterns.h

@@ -594,7 +594,6 @@ class StreamSong : public MusInfo
 {
 public:
     StreamSong (FileReader *reader);
-	StreamSong (const char *url);
 	~StreamSong ();
 	void Play (bool looping, int subsong);
 	void Pause ();

src/sound/i_sound.cpp

@@ -576,11 +576,6 @@ std::pair<SoundHandle,bool> SoundRenderer::LoadSoundVoc(uint8_t *sfxdata, int le
 	return retval;
 }
 
-SoundStream *SoundRenderer::OpenStream(const char *url, int flags)
-{
-    return 0;
-}
-
 SoundDecoder *SoundRenderer::CreateDecoder(FileReader *reader)
 {
     SoundDecoder *decoder = NULL;

src/sound/i_sound.h

@@ -108,7 +108,6 @@ public:
 	// Streaming sounds.
 	virtual SoundStream *CreateStream (SoundStreamCallback callback, int buffbytes, int flags, int samplerate, void *userdata) = 0;
     virtual SoundStream *OpenStream (FileReader *reader, int flags) = 0;
-	virtual SoundStream *OpenStream (const char *url, int flags);
 
 	// Starts a sound.
 	virtual FISoundChannel *StartSound (SoundHandle sfx, float vol, int pitch, int chanflags, FISoundChannel *reuse_chan) = 0;

src/sound/musicformats/music_stream.cpp

@@ -90,11 +90,6 @@ StreamSong::StreamSong (FileReader *reader)
     m_Stream = GSnd->OpenStream (reader, SoundStream::Loop);
 }
 
-StreamSong::StreamSong (const char *url)
-{
-    m_Stream = GSnd->OpenStream (url, SoundStream::Loop);
-}
-
 bool StreamSong::IsPlaying ()
 {
 	if (m_Status != STATE_Stopped)