embed_original: change overflow for the iframe content from hidden to auto

Without this change only a portion of the original website is embedded
in Firefox 20. The Chromium 26 behavior is as expected with hidden and auto.

plugins/embed_original/init.css

@@ -1,12 +1,12 @@
 div.cdmContentInner iframe.embeddedContent {
-	overflow : hidden;
+	overflow : auto;
 	width : 100%;
 	height : 600px;
 	border-width : 0px;
 }
 
 div.postContent iframe.embeddedContent {
-	overflow : hidden;
+	overflow : auto;
 	width : 100%;
 	height : 100%;
 	border-width : 0px;