The creation of the folder for the "installation" of a11y headers is wrong,
so fix that.
copy ..\..\..\gtk\deprecated\gtkvpaned.h $(CopyDir)\include\gtk-$(ApiVersion)\gtk\deprecated
-mkdir $(CopyDir)\include\gtk-$(ApiVersion)\a11y
+mkdir $(CopyDir)\include\gtk-$(ApiVersion)\gtk\a11y
copy ..\..\..\gtk\a11y\gtkarrowaccessible.h $(CopyDir)\include\gtk-$(ApiVersion)\gtk\a11y
copy ..\..\..\gtk\deprecated\gtkvseparator.h $(CopyDir)\include\gtk-$(ApiVersion)\gtk\deprecated
\r
copy ..\..\..\gtk\deprecated\gtkvpaned.h $(CopyDir)\include\gtk-$(ApiVersion)\gtk\deprecated
\r
\r
-mkdir $(CopyDir)\include\gtk-$(ApiVersion)\a11y
\r
+mkdir $(CopyDir)\include\gtk-$(ApiVersion)\gtk\a11y
\r
\r
copy ..\..\..\gtk\a11y\gtkarrowaccessible.h $(CopyDir)\include\gtk-$(ApiVersion)\gtk\a11y
\r
copy ..\..\..\gtk\a11y\gtkbooleancellaccessible.h $(CopyDir)\include\gtk-$(ApiVersion)\gtk\a11y
\r