change in build script: +pdf is used to create pdf:s, rather then -pd…

…f to skip it

build.sh

@@ -1,7 +1,7 @@
 ## enable, for this terminal session, completion for run under bash
 . run.sh --completion--
 
-if [[ ! $1 = "-pdf" ]]; then
+if [[ $1 = "+pdf" ]]; then
     ## create PDF files from dia files
     dia Documentation/CNT_class_diagram.dia    -e Documentation/CNT_class_diagram.pdf    2>/dev/null
     dia Documentation/CNT_join_diagram.dia     -e Documentation/CNT_join_diagram.pdf     2>/dev/null