Getting rid of 'l10n' attribute in the help files

Hi,

As discussed in the other mails, 'l10n' is another attribute I'd like to
remove from the help files.

It is unused in the code, and the documentation says: "Contains the
localization status of the old help files and is only used for migration
purposes." - which has happened years and years ago with the helpcontent
-> helpcontent2 migration :-)

This should not affect the l10n process in any way.

OK to go ahead with this bulk change?

It means the following will be run:

  git grep -l '\<l10n\>' | xargs sed -i 's/\(<paragraph[^>]*\) l10n="[^"]*"/\1/g'

and a small follow-up cleanup for the paragraphs that don't have the
attribute on the same line.  Then I'd remove it from the DTD and
xmlhelp/util/compact.xsl too.

I'll wait until after the ESC call this week, for the case there are any
concerns :-)

All the best,
Kendy