Added 2 step creation to wxPDFViewDocumentFrame

git-svn-id: http://devserv/svn/fluxdvd/components/wxPDFView/trunk@8204 ee4118f4-65c3-8c42-83c6-dbb17464b6b1
Implemented "most visible page" instead of current page

git-svn-id: http://devserv/svn/fluxdvd/components/wxPDFView/trunk@8206 ee4118f4-65c3-8c42-83c6-dbb17464b6b1