texinfo pretest 4.12.90

[Karl Berry]

I've put a new pretest up at
http://alpha.gnu.org/gnu/texinfo/texinfo-4.12.90.tar.gz.  Please test.

NEWS:
* info:
  . support for multibyte encodings such as UTF-8.

* install-info:
  . bug fix: support names with embedded periods (e.g., config.status) again.

* makeinfo:
  . new option --internal-links for HTML output, to write a tsv file
    mapping indexed/toc terms to links, for easy reference from external
    documents.