contrib/xml.rnc

convert: avoid wrong lfconvert defaults by moving configitems to core

The `hg lfconvert --to-normal` command uses the convert extension internally to
work its magic, but that produced devel-warn messages if the convert extension
wasn't loaded by the user.  The test in fcd2f9b06629 (modified here) wasn't
showing the warnings because the convert extension was loaded via $HGRCPATH.
Most of the config options default to None/False, but 'hg.usebranchnames' and
'hg.tagsbranch' are supposed to default to True and 'default' respectively.

The first iteration of this was to ui.setconfig() inside lfconvert, to force the
convert extension to load.  But there really is no precedent for doing this, and
check-config complained that 'extensions.convert' isn't documented.  Yuya
suggested this alternative.

This partially backs out 0d5a1175d0f9.

# RelaxNG schema for "xml" log style
# Inspired by Subversion's XML log format.

start = log
node.type = xsd:string  {minLength = "40" maxLength = "40"}

log = element log { logentry+ }
logentry = element logentry {
    logentry.attlist,
    branch*, tag*, hgparent*,
    author, date,
    msg, paths?, copies?, extra*
}
logentry.attlist =
    attribute revision {xsd:nonNegativeInteger}
  & attribute node {node.type}
branch = element branch { text }
tag = element tag { text }
hgparent = element parent {hgparent.attlist, text}
hgparent.attlist =
    attribute revision {xsd:integer {minInclusive = "-1"} }
  & attribute node {node.type}
author = element author { author.attlist, text }
author.attlist =
    attribute email {text}
date = element date {xsd:dateTime}
msg = element msg {msg.attlist, text}
msg.attlist =
    attribute xml:space {"preserve"}
paths = element paths { path* }
path = element path { path.attlist, text }
path.attlist =
    # Action: (A)dd, (M)odify, (R)emove
    attribute action {"A"|"M"|"R"}
copies = element copies { copy+ }
copy = element copy { copy.attlist, text }
copy.attlist =
    attribute source {text}
extra = element extra {extra.attlist, text}
extra.attlist =
    attribute key {text}