wix: pick up new help topics added between 1.5 and 1.6

These files are not included the 1.6.0 installer, but will be picked up by
nightly builds as soon as this makes it to the stable branch.

contrib/wix/help.wxs

@@ -12,9 +12,12 b''
           <File Name="diffs.txt" />
           <File Name="environment.txt" />
           <File Name="extensions.txt" />
+          <File Name="glossary.txt" />
+          <File Name="hgweb.txt" />
           <File Name="multirevs.txt" />
           <File Name="patterns.txt" />
           <File Name="revisions.txt" />
+          <File Name="revsets.txt" />
           <File Name="templates.txt" />
           <File Name="urls.txt" />
         </Component>