Add support to set the 'title' property of a control such that it will

be displayed when hovering over the control in a control.panel via its 
panel_div. r=me (Closes #822)


git-svn-id: http://svn.openlayers.org/trunk/openlayers@5910 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control.js

@@ -84,6 +84,13 @@ OpenLayers.Control = OpenLayers.Class({
      * Control. 
      */
     displayClass: "",
+    
+    /**
+    * Property: title  
+    * {string}  This property is used for showing a tooltip over the  
+    * Control.  
+    */ 
+    title: "",
 
     /** 
      * Property: active 
@@ -172,6 +179,9 @@ OpenLayers.Control = OpenLayers.Class({
         if (this.div == null) {
             this.div = OpenLayers.Util.createDiv(this.id);
             this.div.className = this.displayClass;
+            if (this.title != "") {
+                this.div.title = this.title;
+            }
         }
         if (px != null) {
             this.position = px.clone();

lib/OpenLayers/Control/Panel.js

@@ -172,6 +172,9 @@ OpenLayers.Control.Panel = OpenLayers.Class(OpenLayers.Control, {
             var element = document.createElement("div");
             var textNode = document.createTextNode(" ");
             controls[i].panel_div = element;
+            if (controls[i].title != "") {
+                controls[i].panel_div.title = controls[i].title;
+            }
             OpenLayers.Event.observe(controls[i].panel_div, "click", 
                 OpenLayers.Function.bind(this.onClick, this, controls[i]));
             OpenLayers.Event.observe(controls[i].panel_div, "mousedown",