numpy.allclose(): check for nan explicitely
Merge pull request #96 from joker-eph/numpy_simplified

numpy.allclose(): check for nan explicitely
Use nt2::is_nan() to test nan instead of x != x trick
Merge pull request #97 from joker-eph/numpy_simplified

Use nt2::is_nan() to test nan instead of x != x trick
Check nt2 is available before validation