2005-01-14  Dave Malcolm  <dmalcolm@redhat.com>

	* shell/ev-view.h:
	* shell/ev-view.c (ev_view_can_go_back), (ev_view_can_go_forward):
	new functions to help with implementation of sensitivity code
	* shell/ev-window.c (update_action_sensitivity): Fix sensitivity
	of all actions that might require it.  Fixes a crash when you
	click on the Zoom actions in a window lacking a document.