Merge branch 'develop' into mplegendre-multi_pkgsrc_roots

Conflicts:
	lib/spack/spack/cmd/create.py
	lib/spack/spack/cmd/extensions.py
	lib/spack/spack/cmd/fetch.py
	lib/spack/spack/cmd/uninstall.py
	lib/spack/spack/config.py
	lib/spack/spack/database.py
	lib/spack/spack/directory_layout.py
	lib/spack/spack/packages.py
	lib/spack/spack/spec.py

var/spack/repos/builtin/packages/glib/package.py

@@ -11,6 +11,7 @@ class Glib(Package):
     version('2.42.1', '89c4119e50e767d3532158605ee9121a')
 
     depends_on("libffi")
+    depends_on("zlib")
 
     def install(self, spec, prefix):
         configure("--prefix=%s" % prefix)