Interpret wxRect passed to wxRichToolTip::ShowFor() as client coords.

It makes more sense to use the window coordinates here instead of the screen
ones.

Closes #15060.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73590 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/wx/richtooltip.h

@@ -182,6 +182,8 @@ public:
         window which must be non-@NULL or, if @a rect is non-@NULL, the middle
         of the specified wxRect.
 
+        The coordinates of the @a rect parameter are relative to the given window.
+
         Currently the native MSW implementation is used only if @a win is a
         wxTextCtrl and @a rect is @NULL. This limitation may be removed in the
         future.