OpenMP shared library loading, fix bug introduced in 0b41090

ctypes.util.find_library needs the lib prefix when using absolute
path.
Fix unittest for itertools.permutations without second argument
Allows list comparison (operator == and !=)

Took the opportunity to improve the implementation for
list_view using std::equal.
Fix itertools permutations

The second argument was not well handled. The implementation is
still by far not the most efficient, and not that clean, but
conformance is improved.
This commit fixes three unittests.
Merge pull request #86 from joker-eph/unittests

Fix itertools unittests, add comparison for list