Don't include wx/cursor.h from wx/dc.h.

This is simply not needed.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76161 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Don't include wx/dc.h from wx/graphics.h.

This is not necessary and prevents compilation of this header in wxUSE_GUI=0
case.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76162 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Include the individual headers that we really need instead.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76163 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775