scmutil: remove dead updatedir code
This code has not been used in a long while.
default = 'changelog'
feedupdated = '<updated>{date|rfc3339date}</updated>'
mimetype = 'application/atom+xml; charset={encoding}'
header = header.tmpl
changelog = changelog.tmpl
changelogentry = changelogentry.tmpl
filelog = filelog.tmpl
filelogentry = filelogentry.tmpl
tags = tags.tmpl
tagentry = tagentry.tmpl
bookmarks = bookmarks.tmpl
bookmarkentry = bookmarkentry.tmpl
branches = branches.tmpl
branchentry = branchentry.tmpl
error = error.tmpl