[PATCH] XML output for hg log

[Robert Bachmann]

Hello,

The patch adds the template file "templates/map-cmdline.xml".
This file provides a simple XML format for changelogs. The format
was modelled after the XML log format used by Subversion.

The typical usage would be:
$ hg log --style xml > changelog.xml

The changeset can be found at:
- http://bitbucket.org/rbachmann/hg-crew-xml/changeset/bf33cfb026a3/

I needed to use the template variable "footer" to write the closing
tag of the XML output. Since "footer" was not supported by
cmdutil.py, I've changed this. Since I'm not entierly certain
about my changes I've provided them in an extra changeset:
- http://bitbucket.org/rbachmann/hg-crew-xml/changeset/4d150b066660/

Thanks,
 Robert Bachmann