Fix up FQCN in doc blocks.

src/Database/Expression/Comparison.php

@@ -284,7 +284,7 @@ class Comparison implements ExpressionInterface, FieldInterface
      * and all ExpressionInterface objects that could be found in the second
      * position.
      *
-     * @param array|Traversable $values The rows to insert
+     * @param array|\Traversable $values The rows to insert
      * @return array
      */
     protected function _collectExpressions($values)

src/Database/ValueBinder.php

@@ -78,7 +78,7 @@ class ValueBinder
      * Creates unique named placeholders for each of the passed values
      * and binds them with the specified type.
      *
-     * @param array|Traversable $values The list of values to be bound
+     * @param array|\Traversable $values The list of values to be bound
      * @param string $type The type with which all values will be bound
      * @return array with the placeholders to insert in the query
      */

src/ORM/Query.php

@@ -52,7 +52,7 @@ use Traversable;
  * @method \Cake\Collection\CollectionInterface take($size = 1, $from = 0) In-memory limit and offset for the query results.
  * @method \Cake\Collection\CollectionInterface skip(int $howMany) Skips some rows from the start of the query result.
  * @method mixed last() Return the last row of the query result
- * @method \Cake\Collection\CollectionInterface append(array|Traversable $items) Appends more rows to the result of the query.
+ * @method \Cake\Collection\CollectionInterface append(array|\Traversable $items) Appends more rows to the result of the query.
  * @method \Cake\Collection\CollectionInterface combine($k, $v, $g = null) Returns the values of the column $v index by column $k,
  *   and grouped by $g.
  * @method \Cake\Collection\CollectionInterface nest($k, $p, $n = 'children') Creates a tree structure by nesting the values of column $p into that