wiki/NaturalDocs says we should be using 'Return:' and not 'Returns:' so this patch is fixing that. Of course, in the process, I came across not a few instances where other ND related whitespace or typos were at odds with a peaceful, uniform OL codebase. No functional changes here, just makin' things pretty.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@4109 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Feature.js

@@ -98,7 +98,7 @@ OpenLayers.Feature = OpenLayers.Class({
     /**
      * Method: onScreen
      * 
-     * Returns:
+     * Return:
      * {Boolean} Whether or not the feature is currently visible on screen
      *           (based on its 'lonlat' property)
      */
@@ -157,7 +157,7 @@ OpenLayers.Feature = OpenLayers.Class({
      * Parameters: 
      * closeBox - {Boolean} create popup with closebox or not
      * 
-     * Returns:
+     * Return:
      * {<OpenLayers.Popup.AnchoredBubble>} 
      * 
      */