Do not include vlc/vlc.h from libvlccore header files

If something depended on this behaviour, it should really be fixed...

include/vlc_streaming.h

@@ -28,8 +28,6 @@
 #ifndef _VLC_STREAMING_H_
 #define _VLC_STREAMING_H_
 
-#include <vlc/vlc.h>
-
 /***********************************************************************
  * Predefined lists of streaming data
  ***********************************************************************/

include/vlc_strings.h

@@ -28,8 +28,6 @@
 #ifndef _VLC_STRINGS_H
 #define _VLC_STRINGS_H 1
 
-#include <vlc/vlc.h>
-
 /**
  * \defgroup strings Strings
  * @{

include/vlc_update.h

@@ -29,8 +29,6 @@
 #ifndef _VLC_UPDATE_H
 #define _VLC_UPDATE_H
 
-#include <vlc/vlc.h>
-
 /**
  * \defgroup update Update
  *