Thanks to Michael Gauland for pointing out this fix
* lisp/ob-plantuml.el (org-babel-execute:plantuml): wrapping in-file
and out-file in shell-quote-argument
* Makefile (LISPF): now compiling and installing ob-plantuml.el
* contrib/scripts/.gitignore : ignores the plantuml.jar file, so that
it can be located next to ditaa.jar
* lisp/ob-plantuml.el: adding copyright notice and FSF attribution
(org-plantuml-jar-path): now a defcustom
(org-babel-execute:plantuml): now using org-babel-eval which
displays error messages
* lisp/org.el (org-babel-load-languages): ob-plantuml is now part of
org-babel-load-languages