Add column separator for help output.

src/main/java/org/elasticsearch/rest/action/cat/AbstractCatAction.java

@@ -49,7 +49,7 @@ public abstract class AbstractCatAction extends BaseRestHandler {
             for (Table.Cell cell : table.getHeaders()) {
                 // need to do left-align always, so create new cells
                 pad(new Table.Cell(cell.value), width[0], request, out);
-                out.append(" ");
+                out.append(" | ");
                 pad(new Table.Cell(cell.attr.containsKey("desc") ? cell.attr.get("desc") : "not available"), width[1], request, out);
                 out.append("\n");
             }