Work around in setup.py for use of numpy during build, also added to install_requires

setup.py

 #!/usr/bin/env python
 # -*- coding: latin-1 -*-
+from setuptools.command.build_ext import build_ext as _build_ext
+
+class build_ext(_build_ext):
+    def finalize_options(self):
+        _build_ext.finalize_options(self)
+        # Prevent numpy from thinking it is still in its setup process:
+        __builtins__.__NUMPY_SETUP__ = False
+        import numpy
+        self.include_dirs.append(numpy.get_include())
 
 
 def get_config_schema():
@@ -205,6 +214,7 @@ def main():
                 ],
 
             install_requires=[
+		"numpy",
                 "pytools>=2014.2",
                 "pytest>=2",
                 "decorator>=3.2.0",