hgweb: fix help pages title in gitweb and monoblue

Help pages in gitweb and monoblue were setting a completely inappropriate
title: "Branches". Let's have a proper title (copy-pasted from paper style).

mercurial/templates/gitweb/help.tmpl

@@ -1,5 +1,5 b''
 {header}
-<title>{repo|escape}: Branches</title>
+<title>Help: {topic}</title>
 <link rel="alternate" type="application/atom+xml"
    href="{url|urlescape}atom-tags" title="Atom feed for {repo|escape}"/>
 <link rel="alternate" type="application/rss+xml"

mercurial/templates/gitweb/helptopics.tmpl

@@ -1,5 +1,5 b''
 {header}
-<title>{repo|escape}: Branches</title>
+<title>Help: {title}</title>
 <link rel="alternate" type="application/atom+xml"
    href="{url|urlescape}atom-tags" title="Atom feed for {repo|escape}"/>
 <link rel="alternate" type="application/rss+xml"

mercurial/templates/monoblue/help.tmpl

@@ -1,5 +1,5 b''
 {header}
-    <title>{repo|escape}: Branches</title>
+    <title>Help: {topic}</title>
     <link rel="alternate" type="application/atom+xml" href="{url|urlescape}atom-log" title="Atom feed for {repo|escape}"/>
     <link rel="alternate" type="application/rss+xml" href="{url|urlescape}rss-log" title="RSS feed for {repo|escape}"/>
 </head>

mercurial/templates/monoblue/helptopics.tmpl

@@ -1,5 +1,5 b''
 {header}
-    <title>{repo|escape}: Branches</title>
+    <title>Help: {title}</title>
     <link rel="alternate" type="application/atom+xml" href="{url|urlescape}atom-log" title="Atom feed for {repo|escape}"/>
     <link rel="alternate" type="application/rss+xml" href="{url|urlescape}rss-log" title="RSS feed for {repo|escape}"/>
 </head>