Add support for Cyrillic in texinfo. (issue 6459081)

[lemzwerg]

Reviewers: ,

Message:
It would be nice if a Russian speaking person could fix the Cyrillic
index entries.  However, since we don't have Cyrillic characters in the
index, this is not an urgent issue (and maybe we never need this).


Description:
Add support for Cyrillic in texinfo.

Please review this at http://codereview.appspot.com/6459081/

Affected files:
  A Documentation/cyrillic.itexi
  M Documentation/macros.itexi