Improving model config error messaging.

 - Fixing issues with fixtures for Mongo relationship integration testing

data/Model.php

@@ -1298,7 +1298,9 @@ public static function &connection() {
 		if ($conn = $connections::get($name)) {
 			return $conn;
 		}
-		throw new ConfigException("The data connection `{$name}` is not configured.");
+		$class = get_called_class();
+		$msg = "The data connection `{$name}` is not configured for model `{$class}`.";
+		throw new ConfigException($msg);
 	}
 
 	/**

tests/fixture/model/gallery/Comments.php

@@ -0,0 +1,16 @@
+<?php
+/**
+ * Lithium: the most rad php framework
+ *
+ * @copyright     Copyright 2013, Union of RAD (http://union-of-rad.org)
+ * @license       http://opensource.org/licenses/bsd-license.php The BSD License
+ */
+
+namespace lithium\tests\fixture\model\gallery;
+
+class Comments extends \lithium\data\Model {
+
+	protected $_meta = array('connection' => 'test');
+}
+
+?>

tests/fixture/model/gallery/Galleries.php

@@ -12,6 +12,7 @@ class Galleries extends \lithium\data\Model {
 
 	public $hasMany = array('Images');
 
+	protected $_meta = array('connection' => 'test');
 }
 
 ?>

tests/fixture/model/gallery/Images.php

@@ -14,6 +14,7 @@ class Images extends \lithium\data\Model {
 
 	public $hasMany = array('ImagesTags', 'Comments');
 
+	protected $_meta = array('connection' => 'test');
 }
 
 ?>

tests/fixture/model/gallery/ImagesTags.php

@@ -12,6 +12,7 @@ class ImagesTags extends \lithium\data\Model {
 
 	public $belongsTo = array('Images', 'Tags');
 
+	protected $_meta = array('connection' => 'test');
 }
 
 ?>