Merge branch 'features/fileutils-deps' into develop

lib/spack/spack/build_environment.py

lib/spack/spack/package.py

lib/spack/spack/packages.py

var/spack/packages/dtcmp/package.py

var/spack/packages/libarchive/package.py

var/spack/packages/libcircle/package.py

var/spack/packages/lwgrp/package.py

var/spack/packages/mvapich2/package.py