Change all 'Parameter:' to 'Parameters:' in documentation. Non functional change

lib/OpenLayers/Layer/Google.js

@@ -205,7 +205,7 @@ OpenLayers.Layer.Google = OpenLayers.Class(
      * APIMethod: setOpacity
      * Sets the opacity for the entire layer (all images)
      * 
-     * Parameter:
+     * Parameters:
      * opacity - {Float}
      */
     setOpacity: function(opacity) {

lib/OpenLayers/Layer/MapServer.js

@@ -114,7 +114,7 @@ OpenLayers.Layer.MapServer = OpenLayers.Class(OpenLayers.Layer.Grid, {
      * Method: getFullRequestString
      * combine the layer's url with its params and these newParams. 
      *   
-     * Parameter:
+     * Parameters:
      * newParams - {Object} New parameters that should be added to the 
      *                      request string.
      * altUrl - {String} (optional) Replace the URL in the full request  

lib/OpenLayers/Layer/Markers.js

@@ -64,7 +64,7 @@ OpenLayers.Layer.Markers = OpenLayers.Class(OpenLayers.Layer, {
      * APIMethod: setOpacity
      * Sets the opacity for all the markers.
      * 
-     * Parameter:
+     * Parameters:
      * opacity - {Float}
      */
     setOpacity: function(opacity) {