Fix the operator precedence table: exponentiation binds tighter than
negation.

This closes SF bug #421999.
diff --git a/Doc/ref/ref5.tex b/Doc/ref/ref5.tex
index ec0c6b1..9590ee4 100644
--- a/Doc/ref/ref5.tex
+++ b/Doc/ref/ref5.tex
@@ -940,11 +940,11 @@
     \lineii{\code{*}, \code{/}, \code{\%}}
            {Multiplication, division, remainder}
   \hline
-    \lineii{\code{**}}				{Exponentiation}
-  \hline
     \lineii{\code{+\var{x}}, \code{-\var{x}}}	{Positive, negative}
     \lineii{\code{\~\var{x}}}			{Bitwise not}
   \hline
+    \lineii{\code{**}}				{Exponentiation}
+  \hline
     \lineii{\code{\var{x}.\var{attribute}}}	{Attribute reference}
     \lineii{\code{\var{x}[\var{index}]}}	{Subscription}
     \lineii{\code{\var{x}[\var{index}:\var{index}]}}	{Slicing}