Bug#865848: Uses await triggers for XML catalogs

[Niels Thykier <niels@thykier.net>]

Package: debhelper,sgml-base
Severity: normal

Hi,

The current sgml-base setup relies on await triggers to carry out its
tasks.  Originally, it was an interest trigger but due to
#825002/#825005, debhelper now inserts an activate trigger instead.

This means that any package that ships XML catalogs can now
potentially start a trigger cycle with sgml-base, which makes the
entire setup frail.
  I have talked with Helmut (X-CC'ed) and concluded that "-noawait"
triggers won't do here.  Accordingly, I think the safest short term
option is to revert to a maintscript snippet.

Thanks,
~Niels