babel: purging all calls to removed org-babel-ref-variables
* lisp/ob-clojure.el (org-babel-prep-session:clojure): purging all
calls to removed org-babel-ref-variables
* lisp/ob-gnuplot.el (org-babel-gnuplot-process-vars): purging all
calls to removed org-babel-ref-variables
* lisp/ob-ruby.el (org-babel-prep-session:ruby): purging all calls to
removed org-babel-ref-variables
* lisp/ob-scheme.el (org-babel-prep-session:scheme): purging all calls
to removed org-babel-ref-variables
* lisp/ob-sqlite.el (org-babel-expand-body:sqlite): purging all calls
to removed org-babel-ref-variables
(org-babel-execute:sqlite): purging all calls to removed
org-babel-ref-variables