merge: rework manifestmerge to use a matcher
This opens the door to working slightly more closely with the manifest
type and letting it optimize out some of the diff comparisons for us,
and also makes life significantly easier for narrowhg.
docheader = '<?xml version="1.0"?>\n<log>\n'
docfooter = '</log>\n'
changeset = '<logentry revision="{rev}" node="{node}">\n{branches}{bookmarks}{tags}{parents}<author email="{author|email|xmlescape}">{author|person|xmlescape}</author>\n<date>{date|rfc3339date}</date>\n<msg xml:space="preserve">{desc|xmlescape}</msg>\n</logentry>\n'
changeset_verbose = '<logentry revision="{rev}" node="{node}">\n{branches}{bookmarks}{tags}{parents}<author email="{author|email|xmlescape}">{author|person|xmlescape}</author>\n<date>{date|rfc3339date}</date>\n<msg xml:space="preserve">{desc|xmlescape}</msg>\n<paths>\n{file_adds}{file_dels}{file_mods}</paths>\n{file_copies}</logentry>\n'
changeset_debug = '<logentry revision="{rev}" node="{node}">\n{branches}{bookmarks}{tags}{parents}<author email="{author|email|xmlescape}">{author|person|xmlescape}</author>\n<date>{date|rfc3339date}</date>\n<msg xml:space="preserve">{desc|xmlescape}</msg>\n<paths>\n{file_adds}{file_dels}{file_mods}</paths>\n{file_copies}{extras}</logentry>\n'
file_add = '<path action="A">{file_add|xmlescape}</path>\n'
file_mod = '<path action="M">{file_mod|xmlescape}</path>\n'
file_del = '<path action="R">{file_del|xmlescape}</path>\n'
start_file_copies = '<copies>\n'
file_copy = '<copy source="{source|xmlescape}">{name|xmlescape}</copy>\n'
end_file_copies = '</copies>\n'
parent = '<parent revision="{rev}" node="{node}" />\n'
branch = '<branch>{branch|xmlescape}</branch>\n'
tag = '<tag>{tag|xmlescape}</tag>\n'
bookmark = '<bookmark>{bookmark|xmlescape}</bookmark>\n'
extra = '<extra key="{key|xmlescape}">{value|xmlescape}</extra>\n'