(\onepageout): Leave only one line space above the footline, to be more

(\onepageout): Leave only one line space above the footline, to be more
like plain.  Suggested by Stephen Gildea.
(\evenfootline): Left one too many line spaces here, so reduce by two.

(\ifnottex): Another ignore command.
(\ifnothtml,\ifnotinfo): New commands.
(\doignore): Ignore brace characters, so mismatched braces in ignored
text do not cause complaints.