display an error if the document doesn't support find (better ideas?)

display an error if the document doesn't support find (better ideas?)

2004-12-22  Havoc Pennington  <hp@redhat.com>

	* shell/ev-window.c (ev_window_cmd_edit_find): display an error if
	the document doesn't support find (better ideas?)
	(find_bar_search_changed_cb): handle missing document or document
	that doesn't support find

	* pdf/xpdf/pdf-document.cc: port to implement the new
	EvDocumentFindIface

	* backend/ev-document-find.c: create a new interface for searching

	* backend/ev-document.h, backend/ev-document.c: delete the find stuff