Closes SF bug 527139. Brings docs inline with random.py 1.29

which fixes the unnecessarily restricted method domain.

Doc/lib/librandom.tex

@@ -218,7 +218,7 @@ these equations can be found in any statistics text.
 
 \begin{funcdesc}{gammavariate}{alpha, beta}
   Gamma distribution.  (\emph{Not} the gamma function!)  Conditions on
-  the parameters are \code{\var{alpha} >= 0.5} and \code{\var{beta} > 0}.
+  the parameters are \code{\var{alpha} > 0} and \code{\var{beta} > 0}.
 \end{funcdesc}
 
 \begin{funcdesc}{gauss}{mu, sigma}