Renamed wxPrintNativeData methods to better match

  Renamed wxPrintNativeData methods to better match
    those of the preexisting wxMac class. This should
    make transition of the wxMac classes to the new
    wxPrintNativeData classes easier.
  Renamed wxWindowsPrintNativeData to a proper name
    that is less confusing (GetNativeData -> GetDevMode).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@29956 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775