hgweb: add tags links and manifest links
This adds a simple new tags page to browse by tag, adds the tag link
everywhere, and adds manifest links to the tags and changelog pages.
header = header.tmpl
footer = footer.tmpl
changelog = changelog.tmpl
naventry = "<a href="?cmd=changelog;rev=#rev#">#rev#</a> "
filedifflink = "<a href="?cmd=filediff;node=#node#;file=#file#">#file#</a> "
filenodelink = "<a href="?cmd=file;filenode=#filenode#;file=#file#">#file#</a> "
fileellipses = "..."
changelogentry = changelogentry.tmpl
changeset = changeset.tmpl
manifest = manifest.tmpl
manifestdirentry = "<div class="parity#parity#"><a href="?cmd=manifest;manifest=#manifest#;path=#path#">#basename#/</a><br /></div>"
manifestfileentry = "<div class="parity#parity#"><a href="?cmd=file;filenode=#filenode#;file=#file#">#basename#</a><br /></div>"
filerevision = filerevision.tmpl
fileannotate = fileannotate.tmpl
filediff = filediff.tmpl
filelog = filelog.tmpl
fileline = "<div class="parity#parity#"><span class="lineno">#linenumber# </span>#line#</div>"
filelogentry = filelogentry.tmpl
annotateline = "<tr class="parity#parity#"><td class="annotate"><a href="?cmd=changeset;node=#node#">#author#@#rev#</a></td><td><pre>#line#</pre></td></tr>"
difflineplus = "<span class="plusline">#line#</span>"
difflineminus = "<span class="minusline">#line#</span>"
difflineat = "<span class="atline">#line#</span>"
diffline = "#line#"
changelogparent = "<tr><td align="right">parent: </td><td><a href="?cmd=changeset;node=#node#">#node#</a></td></tr>"
changesetparent = "<tr><td class="metatag">parent:</td><td><a href="?cmd=changeset;node=#node#">#node#</a></td></tr>"
filerevparent = "<tr><td class="metatag">parent:</td><td><a href="?cmd=file;file=#file#;filenode=#node#">#node#</a></td></tr>"
fileannotateparent = "<tr><td class="metatag">parent:</td><td><a href="?cmd=annotate;file=#file#;filenode=#node#">#node#</a></td></tr>"
tags = tags.tmpl
tagentry = "<div class="parity#parity#"><tt>#node#</tt> <a href="?cmd=changeset;node=#node#">#tag#</a><br /></div>"