contrib/xml.rnc

run-tests: include quotes in the HGEDITOR value when storing sys.executable

This fixes test-install.t on Windows that broke in 2122b82b6987 when
shlex.split() was added to the debuginstall command:

    @@ -7,8 +7,11 @@
       checking installed modules (*mercurial)... (glob)
       checking templates (*mercurial?templates)... (glob)
       checking commit editor...
    +   Can't find editor 'c:\Python27\python.exe -c "(omitted)"' in PATH
    +   (specify a commit editor in your configuration file)
       checking username...
    -  no problems detected
    +  1 problems detected, please check your install!
    +  [1]

What happens is that shlex.split() on Windows turns this:

    c:\Python27\python.exe -c "import sys; sys.exit(0)"

into this:

    ['c:Python27python.exe', '-c', 'import sys; sys.exit(0)']

While technically a regression, most programs on Windows live in some flavor of
'Program Files', and therefore the environment variable needs to contain quotes
anyway to handle the space.  This wasn't handled prior to the shlex() change,
because it tested the whole environment variable to see if it was an executable,
or split on the first space and tested again.

# 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}