Merge branch 'mplegendre-multi_pkgsrc_roots' into develop

- This moves var/spack/packages to var/spack/repos/builtin/packages.

- Packages that did not exist in the source branch, or were changed in
  develop, were moved into var/spack/repos/builtin/packages as part of
  the integration.

Conflicts:
	lib/spack/spack/test/unit_install.py
	var/spack/repos/builtin/packages/clang/package.py

var/spack/repos/builtin/packages/py-pytables/package.py

@@ -0,0 +1,19 @@
+from spack import *
+import re
+
+class PyPytables(Package):
+    """PyTables is a package for managing hierarchical datasets and designed to efficiently and easily cope with extremely large amounts of data."""
+    homepage = "http://www.pytables.org/"
+    url      = "https://github.com/PyTables/PyTables/archive/v.3.2.2.tar.gz"
+
+    version('3.2.2', '7cbb0972e4d6580f629996a5bed92441')
+
+    extends('python')
+    depends_on('hdf5')
+    depends_on('py-numpy')
+    depends_on('py-numexpr')
+    depends_on('py-cython')
+
+    def install(self, spec, prefix):
+        env["HDF5_DIR"] = spec['hdf5'].prefix
+        python('setup.py', 'install', '--prefix=%s' % prefix)