Add source file to generate-benchmark script.

	* tools/generate-benchmark.sh: Add a second optional argument to
	    specify the name of the source file to generate
Add md5 from nettle library.

	* Makefile.am: Add nettle-md5
	* Makefile.in: Regenerate
	* analysis/simulator.in: Add nettle-md5
	* configure: Regenerate
	* configure.ac: Add nettle-md5
	* src/nettle-md5/Makefile.am: Create
	* src/nettle-md5/Makefile.in: Regenerate
	* src/nettle-md5/md5.c: Import md5-compress from the nettle library