r65061 broke PCH-less compilation as it used wxClientDC without (forward) declaring it. Fix this and also correct wxAuiPaneInfo forward declaration. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65072 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775