org.el: Don't add curly braces to bracket links within internal links

org.el: Don't add curly braces to bracket links within internal links

* org.el (org-store-link): When creating a link to a heading
with a bracket link, don't escape this link with curly braces
as the escaped link is not active anyway; use the description
instead.  If the headline only consists of a bracket link, add
a star to the description so that the user knows this is an
internal link.

Thanks to Dave Abrahams for triggering this.