babel: ensuring each language defined (possibly empty) default header arguments

this makes customization easier when users can assume that
  org-babel-default-header-args:foo will exist for every language

lisp/babel/langs/ob-C.el

@@ -36,6 +36,8 @@
 
 (add-to-list 'org-babel-tangle-lang-exts '("c++" . "cpp"))
 
+(defvar org-babel-default-header-args:C '())
+
 (defvar org-babel-C-compiler "gcc"
   "Command used to compile a C source code file into an
   executable.")

lisp/babel/langs/ob-R.el

@@ -35,6 +35,8 @@
 	  pagecentre colormodel useDingbats horizontal)
   "R-specific header arguments.")
 
+(defvar org-babel-default-header-args:R '())
+
 (defun org-babel-expand-body:R (body params &optional processed-params)
   "Expand BODY according to PARAMS, return the expanded body."
   (let* ((processed-params (or processed-params

lisp/babel/langs/ob-clojure.el

@@ -45,6 +45,8 @@
 
 (add-to-list 'org-babel-tangle-lang-exts '("clojure" . "clj"))
 
+(defvar org-babel-default-header-args:clojure '())
+
 (defvar org-babel-clojure-wrapper-method
   "
 (defn spit

lisp/babel/langs/ob-css.el

@@ -30,6 +30,8 @@
 ;;; Code:
 (require 'ob)
 
+(defvar org-babel-default-header-args:css '())
+
 (defun org-babel-expand-body:css (body params &optional processed-params)
   "Expand BODY according to PARAMS, return the expanded body." body)
 

lisp/babel/langs/ob-haskell.el

@@ -46,6 +46,8 @@
 
 (add-to-list 'org-babel-tangle-lang-exts '("haskell" . "hs"))
 
+(defvar org-babel-default-header-args:haskell '())
+
 (defvar org-babel-haskell-lhs2tex-command "lhs2tex")
 
 (defvar org-babel-haskell-eoe "\"org-babel-haskell-eoe\"")

lisp/babel/langs/ob-matlab.el

@@ -39,6 +39,8 @@
 (require 'matlab)
 (require 'ob-octave)
 
+(defvar org-babel-default-header-args:matlab '())
+
 (defvar org-babel-matlab-shell-command "matlab -nosplash"
   "Shell command to use to run matlab as an external process.")
 

lisp/babel/langs/ob-ocaml.el

@@ -41,6 +41,8 @@
 
 (add-to-list 'org-babel-tangle-lang-exts '("ocaml" . "ml"))
 
+(defvar org-babel-default-header-args:ocaml '())
+
 (defvar org-babel-ocaml-eoe-indicator "\"org-babel-ocaml-eoe\";;")
 (defvar org-babel-ocaml-eoe-output "org-babel-ocaml-eoe")
 

lisp/babel/langs/ob-octave.el

@@ -33,6 +33,8 @@
 (require 'ob)
 (require 'octave-inf)
 
+(defvar org-babel-default-header-args:octave '())
+
 (defvar org-babel-octave-shell-command "octave -q"
   "Shell command to use to run octave as an external process.")
 

lisp/babel/langs/ob-perl.el

@@ -31,6 +31,8 @@
 
 (add-to-list 'org-babel-tangle-lang-exts '("perl" . "pl"))
 
+(defvar org-babel-default-header-args:perl '())
+
 (defun org-babel-expand-body:perl (body params &optional processed-params)
   "Expand BODY according to PARAMS, return the expanded body."
   (let ((vars (second (or processed-params (org-babel-process-params params)))))

lisp/babel/langs/ob-python.el

@@ -34,6 +34,8 @@
 
 (add-to-list 'org-babel-tangle-lang-exts '("python" . "py"))
 
+(defvar org-babel-default-header-args:python '())
+
 (defun org-babel-expand-body:python (body params &optional processed-params)
   "Expand BODY according to PARAMS, return the expanded body."
   (concat

lisp/babel/langs/ob-ruby.el

@@ -42,6 +42,8 @@
 
 (add-to-list 'org-babel-tangle-lang-exts '("ruby" . "rb"))
 
+(defvar org-babel-default-header-args:ruby '())
+
 (defun org-babel-expand-body:ruby (body params &optional processed-params)
   "Expand BODY according to PARAMS, return the expanded body."
   (let ((vars (second (or processed-params (org-babel-process-params params)))))

lisp/babel/langs/ob-sass.el

@@ -42,6 +42,8 @@
 (require 'ob)
 (require 'sass-mode)
 
+(defvar org-babel-default-header-args:sass '())
+
 (defun org-babel-expand-body:sass (body params &optional processed-params)
   "Expand BODY according to PARAMS, return the expanded body." body)
 

lisp/babel/langs/ob-sh.el

@@ -41,6 +41,8 @@
 (declare-function org-babel-comint-with-output "ob-comint" (meta &rest body))
 (declare-function orgtbl-to-generic "org-table" (table params))
 
+(defvar org-babel-default-header-args:sh '())
+
 (defvar org-babel-sh-command "sh"
   "Command used to invoke a shell.  This will be passed to
   `shell-command-on-region'")

lisp/babel/langs/ob-sql.el

@@ -45,6 +45,8 @@
 ;;; Code:
 (require 'ob)
 
+(defvar org-babel-default-header-args:sql '())
+
 (defun org-babel-expand-body:sql (body params &optional processed-params)
   "Expand BODY according to PARAMS, return the expanded body." body)
 

lisp/babel/langs/ob-sqlite.el

@@ -29,6 +29,8 @@
 ;;; Code:
 (require 'ob)
 
+(defvar org-babel-default-header-args:sqlite '())
+
 (defun org-babel-expand-body:sqlite
   (body params &optional processed-params) body)