Merge 3.6.

Stefan Krah · Stefan Krah · commit 26581785f362 · 2017-02-04T14:59:11.000+01:00
diff --git a/setup.py b/setup.py
@@ -2015,7 +2015,7 @@ def _decimal_ext(self):
                                                          'Modules',
                                                          '_decimal',
                                                          'libmpdec'))]
-            libraries = []
+            libraries = self.detect_math_libs()
             sources = [
               '_decimal/_decimal.c',
               '_decimal/libmpdec/basearith.c',
