Merge recursive results in DomainParser.parse_clause

We should use jQuery.merge instead of Array.concat, as concat creates a new
Array (which was not correctly returned) and jQuery.merge merges the contents
of both arrays in the first array.

issue5883
review26651003

src/common.js

@@ -1561,7 +1561,7 @@
             var result = [];
             tokens.forEach(function(clause) {
                 if (this.is_generator(clause)) {
-                    result.concat(this.parse_clause(clause));
+                    jQuery.merge(result, this.parse_clause(clause));
                 } else if ((clause == 'OR') || (clause == 'AND')) {
                     result.push(clause);
                 } else if ((clause.length == 1) &&