use pthread_t * handlers rather than pthread_t

pthread-win32 doesn't accept assigning zero to pthread_t type,
so we need to use pointers instead. this is more semantic anyway.

src/lyrics.h

@@ -26,9 +26,6 @@
 #include "screen.h"
 
 #ifdef HAVE_CURL_CURL_H
-# ifdef HAVE_PTHREAD_H
-#  include <pthread.h>
-# endif
 # include "curl/curl.h"
 #endif
 
@@ -88,7 +85,7 @@ class Lyrics : public Screen<Scrollpad>
 		static bool Ready;
 		
 #		ifdef HAVE_PTHREAD_H
-		static pthread_t Downloader;
+		static pthread_t *Downloader;
 #		endif // HAVE_PTHREAD_H
 		
 		static const char *PluginsList[];