Install NFS tracing stuff so we can gather some data.

	* configure, configure.in: Add some nfstrace files.

	* sensors/GNUmakefile.in: Add nfstrace directory to the build.

	* sensors/nfstrace/GNUmakefile.in, nfs.sql, nfsdump2db,
	nfstrace.init.in, nfstrace.proxy: Prototype of scripts to trace
	NFS traffic from experimental nodes and build a list of the files
	that are accessed.

	* sensors/nfstrace/nfsdump2/*: Slightly customized version of the
	nfsdump program.

	* tbsetup/GNUmakefile.in: Install nfstrace control script which is
	used to talk to the proxy on ops.