reference links should be able to have their names on the next line

Parsedown.php

@@ -528,7 +528,7 @@ class Parsedown
 		
 		# Reference(d) Link / Image 
 		
-		if ($this->reference_map and strpos($text, '[') !== FALSE and preg_match_all('/(!?)\[(.+?)\](?:[ ]?\[(.*?)\])?/ms', $text, $matches, PREG_SET_ORDER))
+		if ($this->reference_map and strpos($text, '[') !== FALSE and preg_match_all('/(!?)\[(.+?)\](?:\n?[ ]?\[(.*?)\])?/ms', $text, $matches, PREG_SET_ORDER))
 		{
 			foreach ($matches as $matches)
 			{

tests/data/reference_link.html

@@ -4,6 +4,7 @@
 <p>Here's <a href="http://parsedown.org">one</a> on 2 lines.</p>
 <p>Here's <a href="http://parsedown.org/tests/">one</a> with a different URL.</p>
 <p>Here's <a href="http://parsedown.org">one</a> with a semantic name.</p>
+<p>Here's <a href="http://parsedown.org">one</a> with definition name on the next line.</p>
 <p>Here's [one][404] with no definition.</p>
 <p>Here's an image: <img alt="Markdown Logo" src="https://raw.github.com/dcurtis/markdown-mark/master/png/32x20-solid.png"></p>
 <p>Here's an <a href="http://google.com">implicit one</a>.</p>

tests/data/reference_link.md

@@ -22,6 +22,9 @@ Here's [one][website] with a semantic name.
 
 [website]: http://parsedown.org
 
+Here's [one]
+[website] with definition name on the next line.
+
 Here's [one][404] with no definition.
 
 Here's an image: ![Markdown Logo][image]