reduce impact of driver/pictureviewer.h header file

before, more than 175 files depended on it, now it's about 35

src/gui/screensaver.cpp

@@ -43,6 +43,7 @@
 #include <gui/color_custom.h>
 #include <gui/infoclock.h>
 #include <zapit/zapit.h>
+#include <driver/pictureviewer/pictureviewer.h>
 
 #include <video.h>
 extern cVideo * videoDecoder;
@@ -315,4 +316,4 @@ bool CScreenSaver::IsRun()
 	if(thrScreenSaver)
 		return true;
 	return false;
-}
+}