add new C api function ModPlug_Tell to get the playing position in msecs

the function was originally authored and is provided by Vitaly Novichkov.

increase the version number to 0.8.10 so the new functions can be checked
easily at compile time.

src/modplug.cpp

@@ -270,6 +270,21 @@ void ModPlug_Seek(ModPlugFile* file, int millisecond)
 	file->mSoundFile.SetCurrentPos((int)(millisecond * postime));
 }
 
+int ModPlug_Tell(ModPlugFile *file)
+{
+	int currentPos = (int)file->mSoundFile.GetCurrentPos();
+	int maxpos;
+	int maxtime = (int)file->mSoundFile.GetSongTime() * 1000;
+	float postime;
+	maxpos = (int)file->mSoundFile.GetMaxPosition();
+	postime = 0.0f;
+	if (maxtime != 0.0f)
+	    postime = (float)maxpos / (float)maxtime;
+	if (postime == 0.0f)
+	    return 0;
+	return (int) ((float)currentPos / postime);
+}
+
 void ModPlug_GetSettings(ModPlug_Settings* settings)
 {
 	memcpy(settings, &ModPlug::gSettings, sizeof(ModPlug_Settings));

src/modplug.h

@@ -13,8 +13,8 @@ extern "C" {
 
 #define LIBMODPLUG_MAJOR		0L
 #define LIBMODPLUG_MINOR		8L
-#define LIBMODPLUG_REVISION		9L
-#define LIBMODPLUG_PATCH		1L
+#define LIBMODPLUG_REVISION		10L
+#define LIBMODPLUG_PATCH		0L
 #define LIBMODPLUG_VERSION		\
     ((LIBMODPLUG_MAJOR   <<24) |	\
      (LIBMODPLUG_MINOR   <<16) |	\
@@ -79,6 +79,9 @@ MODPLUG_EXPORT int ModPlug_GetLength(ModPlugFile* file);
  * ModPlug_GetLength() does not report the full length. */
 MODPLUG_EXPORT void ModPlug_Seek(ModPlugFile* file, int millisecond);
 
+/* Get the absolute playing position in song, in milliseconds. */
+MODPLUG_EXPORT int ModPlug_Tell(ModPlugFile* file);
+
 enum _ModPlug_Flags
 {
 	MODPLUG_ENABLE_OVERSAMPLING     = 1 << 0,  /* Enable oversampling (*highly* recommended) */