CSRF whitelist supports regex

Signed-off-by: Casey Hancock <crh431@gmail.com>
diff --git a/system/core/Security.php b/system/core/Security.php
index 741ff22..a6fd75f 100755
--- a/system/core/Security.php
+++ b/system/core/Security.php
@@ -203,10 +203,13 @@
 		if ($exclude_uris = config_item('csrf_exclude_uris'))
 		{
 			$uri = load_class('URI', 'core');
-			if (in_array($uri->uri_string(), $exclude_uris))
-			{
-				return $this;
-			}
+			foreach ($exclude_uris as $excluded) {
+                		$excluded = str_replace(array(':any', ':num'), array('[^/]+', '[0-9]+'), $excluded);
+                		if (preg_match('#^'.$excluded.'$#', $uri->uri_string()))
+                		{
+                    			return $this;
+                		}
+            		}
 		}
 
 		// Do the tokens exist in both the _POST and _COOKIE arrays?