adding google sparsehash and cityhash libraries

var/spack/packages/cityhash/package.py

+from spack import *
+from spack.util.environment import *
+
+class Cityhash(Package):
+    homepage = "https://github.com/google/cityhash"
+    url      = "https://github.com/google/cityhash"
+
+    version('2013-07-31', git='https://github.com/google/cityhash.git', commit='8af9b8c2b889d80c22d6bc26ba0df1afb79a30db')
+    version('master', branch='master', git='https://github.com/google/cityhash.git')
+
+    def install(self, spec, prefix):
+        configure('--enable-sse4.2', '--prefix=%s' % prefix)
+
+        make()
+        make("install")
+

var/spack/packages/jemalloc/package.py

@@ -7,8 +7,18 @@ class Jemalloc(Package):
 
     version('4.0.4', '687c5cc53b9a7ab711ccd680351ff988')
 
+    variant('stats', default=False, description='Enable heap statistics')
+    variant('prof', default=False, description='Enable heap profiling')
+
     def install(self, spec, prefix):
-        configure('--prefix=%s' % prefix)
+        configure_args = ['--prefix=%s' % prefix,]
+
+        if '+stats' in spec:
+            configure_args.append('--enable-stats')
+        if '+prof' in spec:
+            configure_args.append('--enable-prof')
+
+        configure(*configure_args)
 
         make()
         make("install")

var/spack/packages/sparsehash/package.py

+from spack import *
+
+class Sparsehash(Package):
+    """Sparse and dense hash-tables for C++ by Google"""
+    homepage = "https://github.com/sparsehash/sparsehash"
+    url      = "https://github.com/sparsehash/sparsehash/archive/sparsehash-2.0.3.tar.gz"
+
+    version('2.0.3', 'd8d5e2538c1c25577b3f066d7a55e99e')
+
+    def install(self, spec, prefix):
+        configure('--prefix=%s' % prefix)
+
+        make()
+        make("install")