Continuation of Issue 210:Bottom pixels not complete visable in some zoom modes. I chose to have a dead zone at bottom of zoomed area only when it's at bottom of image too. The dead zone is created only if the remaining space is <= 50 of a normal zoomed line, So the usable pixels are guaranteed to be > half a normal line, and the dead space is always <= half a line.

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1445 416bcca6-2ee7-4201-b75f-2eb2f807beb1

src/windows.h

@@ -46,6 +46,7 @@ void Remap_menu_sprites();
 void Position_screen_according_to_zoom(void);
 void Compute_separator_data(void);
 void Compute_magnifier_data(void);
+void Clip_magnifier_offsets(short *x_offset, short *y_offset);
 void Compute_limits(void);
 void Compute_paintbrush_coordinates(void);