remove calls to deprecated clearCellSelection (followup to hyatt's checkin)

mailnews/base/prefs/resources/content/SmtpServerList.js

@@ -108,7 +108,6 @@ function refreshServerList()
     // save selection
     var oldSelectedIds = new Array;
     serverList.clearItemSelection();
-    serverList.clearCellSelection();
     var selectedItems = serverList.selectedItems;
     for (var i=0; i< selectedItems.length; i++)
         oldSelectedIds[i] = selectedItems[0].id;

mailnews/base/resources/content/msgMail3PaneWindow.js

@@ -733,7 +733,6 @@ function ChangeSelection(tree, newSelection)
 	if(newSelection)
 	{
 		tree.clearItemSelection();
-		tree.clearCellSelection();
 		tree.selectItem(newSelection);
 		tree.ensureElementIsVisible(newSelection);
 	}

mailnews/base/resources/content/widgetglue.js

@@ -99,7 +99,6 @@ function RenameFolder(name,uri)
 	if (uri && (uri != "") && name && (name != "")) {
                 var selectedFolder = GetResourceFromUri(uri);
                 folderTree.clearItemSelection();
-                folderTree.clearCellSelection();
                 messenger.RenameFolder(folderTree.database, selectedFolder, name);
         }
         else {
@@ -202,7 +201,6 @@ function MsgCompactFolder()
                 ChangeSelection(tree, selectedFolder);
                 */
                 tree.clearItemSelection();
-                tree.clearCellSelection();
             }
         }
 	}

mailnews/base/search/resources/content/FilterListDialog.js

@@ -195,7 +195,6 @@ function refreshFilterList() {
         selection = tree.selectedItems[0].id;
 
     tree.clearItemSelection();
-    tree.clearCellSelection();
     tree.setAttribute("ref", tree.getAttribute("ref"));
 
     if (selection) {