Add PSAPI

var/spack/packages/psapi/package.py

+from spack import *
+
+class Psapi(Package):
+    """PSAPI is a library and a tool for collecting sampled memory
+    performance data to view with MemAxes"""
+
+    homepage = "https://github.com/scalability-llnl/PSAPI"
+    url      = "http://www.example.com/memaxes-psapi-1.0.tar.gz"
+
+    version('0.5', git='https://github.com/scalability-llnl/PSAPI.git', tag='v0.5')
+
+    depends_on('dyninst')
+
+    def install(self, spec, prefix):
+        with working_dir('spack-build', create=True):
+            cmake('..', *std_cmake_args)
+            make()
+            make("install")