org: move babel's temporary directory in builddir

Fixes #244, reported by Vincent Tourneur.

* doc/org/.dir-locals.el.in, doc/org/init.el.in: Define
org-babel-temporary-directory and create the directory.

doc/org/.dir-locals.el.in

@@ -24,14 +24,16 @@
 				      (getenv "DYLD_LIBRARY_PATH")))
 		      (setenv "SPOT_DOTDEFAULT" "Brf(Lato)C(#ffffa0)")
 		      (setenv "SPOT_DOTEXTRA" "edge[arrowhead=vee, arrowsize=.7]")
+                      (setq org-babel-temporary-directory "@abs_top_builddir@/doc/org/tmp")
+                      (make-directory org-babel-temporary-directory t)
 		      (org-babel-do-load-languages 'org-babel-load-languages
                                                    `((,(if (version< org-version "8.3") 'sh 'shell) . t)
 						     (python . t)
                                                      (plantuml . t)
 						     (dot . t)
 						     (C . t)))))
-              (org-plantuml-jar-path . "@abs_top_builddir@/doc/org/plantuml.jar")
 	      (org-confirm-babel-evaluate . nil)
+              (org-plantuml-jar-path . "@abs_top_builddir@/doc/org/plantuml.jar")
 	      (org-babel-python-command . "@PYTHON@")
 	      (org-babel-C++-compiler . "./g++wrap")
 	      (shell-file-name . "@SHELL@")

doc/org/init.el.in

@@ -28,6 +28,8 @@
    (C . t)))
 (setq org-confirm-babel-evaluate nil)
 (setq org-plantuml-jar-path "@abs_top_builddir@/doc/org/plantuml.jar")
+(setq org-babel-temporary-directory "@abs_top_builddir@/doc/org/tmp")
+(make-directory org-babel-temporary-directory t)
 (setq org-babel-python-command "@PYTHON@")
 (setq org-babel-C++-compiler "./g++wrap")
 (setq shell-file-name "@SHELL@")
@@ -90,3 +92,7 @@
        ("spot-all" :components ("spot-html" "spot-static"))))
 
 (org-publish-all t)
+;;; org-babel-remove-temporary-directory does not correctly remove
+;;; nested directories and we have some files in tmp/.libs/ because of
+;;; libtool.  So let us clean that ourselves.
+(delete-directory org-babel-temporary-directory t)