Normalized associated models in unbindModel.

 Resolves #1764

 Had to cast $models to an array since ``Hash::normalize()`` doesn't support strings which ``Set::normalize()`` does (but which is deprecated).
 Reused existing tests.

lib/Cake/Model/Model.php

@@ -953,9 +953,11 @@ public function bindModel($params, $reset = true) {
  * Example: Turn off the associated Model Support request,
  * to temporarily lighten the User model:
  *
- * `$this->User->unbindModel( array('hasMany' => array('Supportrequest')) );`
+ * `$this->User->unbindModel(array('hasMany' => array('SupportRequest')));`
+ * Or alternatively:
+ * `$this->User->unbindModel(array('hasMany' => 'SupportRequest'));`
  *
- * unbound models that are not made permanent will reset with the next call to Model::find()
+ * Unbound models that are not made permanent will reset with the next call to Model::find()
  *
  * @param array $params Set of bindings to unbind (indexed by binding type)
  * @param boolean $reset Set to false to make the unbinding permanent
@@ -967,7 +969,7 @@ public function unbindModel($params, $reset = true) {
 			if ($reset === true && !isset($this->__backAssociation[$assoc])) {
 				$this->__backAssociation[$assoc] = $this->{$assoc};
 			}
-
+			$models = Hash::normalize((array)$models, false);
 			foreach ($models as $model) {
 				if ($reset === false && isset($this->__backAssociation[$assoc][$model])) {
 					unset($this->__backAssociation[$assoc][$model]);

lib/Cake/Test/Case/Model/ModelReadTest.php

@@ -2181,10 +2181,10 @@ public function testRecursiveUnbind() {
 
 		$this->assertEquals($expected, $result);
 
-		$result = $TestModel->unbindModel(array('hasMany' => array('Child')));
+		$result = $TestModel->unbindModel(array('hasMany' => 'Child'));
 		$this->assertTrue($result);
 
-		$result = $TestModel->Sample->unbindModel(array('belongsTo' => array('Apple')));
+		$result = $TestModel->Sample->unbindModel(array('belongsTo' => 'Apple'));
 		$this->assertTrue($result);
 
 		$result = $TestModel->find('all');