Implement suggestion from #318 for multicron format.

Author: jmrozanec

src/main/java/com/cronutils/parser/CronParser.java

@@ -93,6 +93,10 @@ public Cron parse(final String expression) {
             throw new IllegalArgumentException("Empty expression!");
         }
 
+        if(expression.contains("||")) {
+            List<Cron> crons = Arrays.stream(expression.split("\\|\\|")).map(this::parse).collect(Collectors.toList());
+            return new CompositeCron(crons);
+        }
         if(expression.contains("|")){
             List<String> crons = new ArrayList<>();
             int cronscount = Arrays.stream(expression.split("\\s+")).mapToInt(s->s.split("\\|").length).max().orElse(0);
@@ -107,7 +111,7 @@ public Cron parse(final String expression) {
                 }
                 crons.add(builder.toString().trim());
             }
-            return new CompositeCron(crons.stream().map(c->parse(c)).collect(Collectors.toList()));
+            return new CompositeCron(crons.stream().map(this::parse).collect(Collectors.toList()));
         }else{
             final String[] expressionParts = replaced.toUpperCase().split(" ");
             final int expressionLength = expressionParts.length;