hgweb: Search templates in templatepath/style/map, too, using a common function.
This allows for web templates to be self-contained in a directory, which makes
copying and modifying them easier.
default = 'changelog'
header = rss/header.tmpl
changelog = rss/changelog.tmpl
changelogentry = rss/changelogentry.tmpl
filelog = rss/filelog.tmpl
filelogentry = rss/filelogentry.tmpl
tags = rss/tags.tmpl
tagentry = rss/tagentry.tmpl