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/expat/package.py

@@ -0,0 +1,17 @@
+from spack import *
+
+class Expat(Package):
+    """<eXpat/> is an XML parser library written in C"""
+    homepage = "http://expat.sourceforge.net/"
+    url      = "http://downloads.sourceforge.net/project/expat/expat/2.1.0/expat-2.1.0.tar.gz"
+
+    version('2.1.0', 'dd7dab7a5fea97d2a6a43f511449b7cd')
+
+
+    def install(self, spec, prefix):
+
+        with working_dir('spack-build', create=True):
+            cmake('..', *std_cmake_args)
+            make()
+            make('install')
+