* components/sample/nautilus-sample-content-view.c,
	components/sample/nautilus-sample-content-view.h,
	components/sample/nautilus-sample-content-view.goad,
	components/sample/main.c, components/sample/Makefile.am: Sample
	content view component. All it does is display the current URI in
	a label.
	* componets/Makefile.am, configure.in: Build it.
	* src/ntl-uri-map.c: Activate the sample component whenever there
	is at least one other applicable view. What it should really do is
	have a special mode based on a command-line option of some sort
	which will cause it to be always activated, and otherwise not at
	all, but that looked more complicated to do.