Re-add numba wrapper that was mistakenly removed

numba_wrapper.py

@@ -0,0 +1,49 @@
+# Copyright (c) 2017, Michael Boyle
+# See LICENSE file for details: <https://github.com/moble/quaternion/blob/master/LICENSE>
+
+from __future__ import division, print_function, absolute_import
+
+## Allow the code to function without numba, but discourage it
+## strongly.
+try:
+    from numbapro import njit, jit, vectorize, int64, float64, complex128
+    from numba.utils import IS_PY3
+
+    GOT_NUMBA = True
+except ImportError:
+    try:
+        from numba import njit, jit, vectorize, int64, float64, complex128
+        from numba.utils import IS_PY3
+
+        GOT_NUMBA = True
+    except ImportError:
+        import warnings
+        import sys
+
+        warning_text = \
+            "\n\n" + "!" * 53 + "\n" + \
+            "Could not import from either numbapro or numba.\n" + \
+            "This means that the code will run MUCH more slowly.\n" + \
+            "You probably REALLY want to install numba / numbapro." + \
+            "\n" + "!" * 53 + "\n"
+        warnings.warn(warning_text)
+
+        def _identity_decorator_outer(*args, **kwargs):
+            def _identity_decorator_inner(fn):
+                return fn
+
+            return _identity_decorator_inner
+
+        njit = _identity_decorator_outer
+        jit = _identity_decorator_outer
+        vectorize = _identity_decorator_outer
+        int64 = int
+        float64 = float
+        complex128 = complex
+        IS_PY3 = (sys.version_info[:2] >= (3, 0))
+        GOT_NUMBA = False
+
+if IS_PY3:
+    xrange = range
+else:
+    xrange = xrange