Update space dispatch:

- drawXXXspace, changeXXXspace, and winqreadXXXspace now receive the area
     and spacedata as explicit arguments, allowing them to access private
     data w/o going through globals.
 - pass the new BWinEvent through to the winqreadXXXspace, allowing future
     access to extended event data.

Removed direct calls to winqreadXXXspace to simulate user actions, replaced
by calls to action functions in edit.c or the appropriate handler.

source/blender/include/BIF_drawimage.h

@@ -33,10 +33,11 @@
 #ifndef BIF_DRAWIMAGE_H
 #define BIF_DRAWIMAGE_H
 
+struct ScrArea;
 struct SpaceImage;
 
 void calc_image_view(struct SpaceImage *sima, char mode);
-void drawimagespace(void);
+void drawimagespace(struct ScrArea *sa, void *spacedata);
 void draw_tfaces(void);
 void image_changed(struct SpaceImage *sima, int dotile);
 void image_home(void);