Speed up function calls into the math module by using METH_O.
There should be no functional changes. However, the error msgs are
slightly different.  Also verified that the module dict is not NULL on init.
diff --git a/Misc/NEWS b/Misc/NEWS
index 849911b..0e2969e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -236,6 +236,8 @@
 Extension Modules
 -----------------
 
+- Speed up function calls into the math module.
+
 - Bug #1588217: don't parse "= " as a soft line break in binascii's
   a2b_qp() function, instead leave it in the string as quopri.decode()
   does.