incorrect HTML rendering of info links with spaces

[emacs18@gmail.com (Richard Y. Kim)]

It seems like org-html-publish-to-html does not translate info links
properly in generated HTML files.  The problem is that spaces in info
nodes should be converted to dashes, but instead spaces are left as is.

For example org-mode link [[info:elisp#Hash Tables]] is converted as 

    <a href="elisp#Hash Tables">elisp#Hash Tables</a>

when in fact the correct URL that should be generated is

    <a href="elisp.html#Hash-Tables">elisp#Hash Tables</a>

where a dash is used in the URL as well as ".html" suffix.

Why should it be "-" instead of " "?  Simply because that is the
convention used by GNU makeinfo when translating texinfo files into HTML
output.  For example

    http://www.gnu.org/software/emacs/manual/html_mono/elisp.html#Hash-Tables

is the correct URL rather than this incorrect URL:

    http://www.gnu.org/software/emacs/manual/html_mono/elisp.html#Hash%20Tables

So today if I hit C-c C-o on [[info:elisp#Hash Tables]] link, then it
correctly brings up "(elisp) Hash Tables" info node.  However the
generated HTML link does not work.  On the other hand
[[info:elisp#Hash-Tables]] with a dash rather than space generates valid
HTML link (ignoring missing ".html" suffix), but C-c C-o fails to work.
It would be very useful if the same org link such as [[info:elisp#Hash
Tables]] works for both C-c C-o as well as generate valid HTML link.

This issue is important to me, because I would rather use org-mode than
texinfo to write documentation on emacs packages with many links
pointing to the official emacs and elisp manuals.  Right now lack of
proper support for info links in org-mode is the *only* reason why I
currently use texinfo rather than org-mode.