py: Include mpconfig.h before all other includes.

It defines types used by all other headers.

Fixes #691.
diff --git a/py/compile.c b/py/compile.c
index b9979af..d49edd6 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -31,8 +31,8 @@
 #include <assert.h>
 #include <math.h>
 
-#include "misc.h"
 #include "mpconfig.h"
+#include "misc.h"
 #include "qstr.h"
 #include "lexer.h"
 #include "parse.h"