Continue refactoring of global state

src/main.h

@@ -2,6 +2,7 @@
 
 #include "gtk/gtk.h"
 #include "process_pipeline.h"
+#include "state.h"
 #include "zbar_pipeline.h"
 
 struct mp_main_state {
@@ -22,7 +23,7 @@ struct mp_main_state {
         int image_height;
 };
 
-void mp_main_update_state(const struct mp_main_state *state);
+void mp_main_update_state(const mp_state_main *new_state);
 
 void mp_main_set_preview(MPProcessPipelineBuffer *buffer);
 void mp_main_capture_completed(GdkTexture *thumb, const char *fname);