ox-publish: Change signature for preparation and completion functions
* doc/org.texi (Sources and destinations): Document new signature.
* lisp/ox-publish.el (org-publish-project-alist): Update docstring.
(org-publish-projects): Call preparation and
completion functions with the project properties as the sole argument.
`project-plist' used to be dynamically scoped. This is no longer
possible due to the switch to lexical binding.
Reported-by: Arun Isaac <arunisaac@systemreboot.net>
<http://permalink.gmane.org/gmane.emacs.orgmode/107856>