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/src/drawipo.c

@@ -358,6 +358,16 @@ int in_ipo_buttons(void)
 }
 
 
+void view2d_zoom(View2D *v2d, float factor, int winx, int winy) {
+	float dx= factor*(v2d->cur.xmax-v2d->cur.xmin);
+	float dy= factor*(v2d->cur.ymax-v2d->cur.ymin);
+	v2d->cur.xmin+= dx;
+	v2d->cur.xmax-= dx;
+	v2d->cur.ymin+= dy;
+	v2d->cur.ymax-= dy;
+	test_view2d(v2d, winx, winy);
+}
+
 void test_view2d(View2D *v2d, int winx, int winy)
 {
 	/* cur mag niet groter dan max, kleiner dan min of buiten tot vallen */
@@ -1316,7 +1326,7 @@ static void draw_key(SpaceIpo *sipo, int visible)
 	setlinestyle(0);
 }
 
-void drawipospace(void)
+void drawipospace(ScrArea *sa, void *spacedata)
 {
 	SpaceIpo *sipo= curarea->spacedata.first;
 	View2D *v2d= &sipo->v2d;