Unlike the old function just indicating whether a printout is being used for previewing, the new one associates the preview object with it. This can be useful if we need to access the window used for the preview, for example. Also remove a bunch of apparently unnecessary SetIsPreview(false) calls as printing (and not previewing) is already the default. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@64212 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775