babel: variable references which look like lisp forms are now evaluated
for example, the following simple example
#+begin_src emacs-lisp :var two=(+ 1 1)
(sqrt two)
#+end_src
#+results:
: 1.
4142135623730951
Or this more interesting usage, which pulls variable values from
headline properties
*** example headline w/property
:PROPERTIES:
:special: 89
:last-name: schulte
:END:
#+begin_src emacs-lisp :var special=(string-to-number (org-entry-get nil "special" t))
(+ special 1)
#+end_src
#+results:
: 90
#+begin_src emacs-lisp :var last-name=(org-entry-get nil "last-name" t))
(message "hello %s" last-name)
#+end_src
#+results:
: hello schulte