Item12407: Call no_expand_entities if possible

The real fix for Compare entity encoding issues is to use a modern
version of HTML::TreeBuilder and set the no_expand_entites flag.
Otherwise, when the topic is imported, all entities are decoded,
"activating" encoded tags.

git-svn-id: http://svn.foswiki.org/branches/Release01x01@17631 0b4bb1d4-4e5a-0410-9cc4-b2b747904278