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/drawsound.c

@@ -60,7 +60,7 @@
 #include "BSE_drawipo.h"
 
 /* local */
-void drawsoundspace(void);
+void drawsoundspace(ScrArea *sa, void *spacedata);
 
 /*implementation */
 static void draw_wave(int startsamp, int endsamp, short sampdx, short offset, short *sp, float sampfac, float y)
@@ -163,7 +163,7 @@ static void draw_cfra_sound(void)
 }
 
 
-void drawsoundspace(void)
+void drawsoundspace(ScrArea *sa, void *spacedata)
 {
 	short ofsx, ofsy;