doc fix: hg tags defaults to current parent revision, too.
Additionally use better language for the help text for tag,
cat and manifest.
#header#
<title>#repo|escape#: tags</title>
<link rel="alternate" type="application/rss+xml"
href="#url#rss-tags" title="RSS feed for #repo|escape#: tags">
</head>
<body>
<div class="buttons">
<a href="#url#log{sessionvars%urlparameter}">changelog</a>
<a href="#url#shortlog{sessionvars%urlparameter}">shortlog</a>
<a href="#url#file/#node|short#/{sessionvars%urlparameter}">manifest</a>
<a type="application/rss+xml" href="#url#rss-tags">rss</a>
</div>
<h2>tags:</h2>
<ul id="tagEntries">
#entries%tagentry#
</ul>
#footer#