Sequencer new option to open sequence config file when initialised using initSeqConfig

Sequences with exit in step_config, changed to return to support opening config file on first run

seqs/piwigo.sh

@@ -20,7 +20,7 @@ step_config() {
   if [ $? -eq 0 ] ; then
     CONFIG=1
   else
-    exit 1
+    [ $DRY -eq 0 ] && return 1
   fi
 }