Added definitions of \refbimodindex{} and \refstmodindex{}, which should be
used to add index references for built-in and standard modules, respectively.

Modified \bimodindex{} and \stmodindex{} to make the page number bold, to
allow the defining instance of a module to stand out in the index.

Check-ins which fix improper use of \bimodindex{} and \stmodindex{} will be
made as fixes are applied.  Misc. indexing updates will occur as a side
effect in some cases.
diff --git a/Doc/myformat.sty b/Doc/myformat.sty
index 0a42b40..50698b9 100644
--- a/Doc/myformat.sty
+++ b/Doc/myformat.sty
@@ -96,9 +96,14 @@
 \newcommand{\bifuncindex}[1]{\index{#1@{\tt#1} (built-in function)}}
 
 % Add an index entry for a module
-\newcommand{\modindex}[2]{\index{#1@{\tt#1} (#2module)}}
-\newcommand{\bimodindex}[1]{\modindex{#1}{built-in }}
-\newcommand{\stmodindex}[1]{\modindex{#1}{standard }}
+\newcommand{\refmodule}[2]{\index{#1@{\tt#1} (#2module)}}
+\newcommand{\refbimodindex}[1]{\refmodule{#1}{built-in }}
+\newcommand{\refstmodindex}[1]{\refmodule{#1}{standard }}
+
+% Add the defining entry for a module
+\newcommand{\defmodindex}[2]{\index{#1@{\tt#1} (#2module)|textbf}}
+\newcommand{\bimodindex}[1]{\defmodindex{#1}{built-in }}
+\newcommand{\stmodindex}[1]{\defmodindex{#1}{standard }}
 
 % Additional string for an index entry
 \newcommand{\indexsubitem}{}