Extend openmc.data to be able to import ENDF data and perform resonance

reconstruction.

setup.py

@@ -8,6 +8,12 @@ except ImportError:
     from distutils.core import setup
     have_setuptools = False
 
+try:
+    from Cython.Build import cythonize
+    have_cython = True
+except ImportError:
+    have_cython = False
+
 kwargs = {'name': 'openmc',
           'version': '0.8.0',
           'packages': ['openmc', 'openmc.data', 'openmc.mgxs', 'openmc.model',
@@ -48,4 +54,10 @@ if have_setuptools:
         },
     })
 
+# If Cython is present, add resonance reconstruction capability
+if have_cython:
+    kwargs.update({
+        'ext_modules': cythonize('openmc/data/reconstruct.pyx')
+    })
+
 setup(**kwargs)