[FIXED][3.0] Menu getItemArgs (isXType vs instanceof)

[stever]

I suppose this one may be considered a difference of opinion, but it caused upgrade havoc so I think it is at least worth thinking about. In Menu.js, getItemArgs looks like this now:

Original:

    getItemArgs: function(c) {
        var isMenuItem = c.isXType(Ext.menu.Item);
        return {
            isMenuItem: isMenuItem,
            needsIcon: !isMenuItem && (c.icon || c.iconCls),
            icon: c.icon || Ext.BLANK_IMAGE_URL,
            iconCls: 'x-menu-item-icon ' + (c.iconCls || ''),
            itemId: 'x-menu-el-' + c.id,
            itemCls: 'x-menu-list-item ' + (this.extraCls || '')
        };
    } 

As opposed to this:
Proposed:

    getItemArgs: function(c) {
        var isMenuItem = c instanceof Ext.menu.Item;
        return {
            isMenuItem: isMenuItem,
            needsIcon: !isMenuItem && (c.icon || c.iconCls),
            icon: c.icon || Ext.BLANK_IMAGE_URL,
            iconCls: 'x-menu-item-icon ' + (c.iconCls || ''),
            itemId: 'x-menu-el-' + c.id,
            itemCls: 'x-menu-list-item ' + (this.extraCls || '')
        };
    } 

The side effect of using isXType is that every subclass must register an xtype or the menus get created all wrong. I prefer the way Ext2 did it, which is the proposed change (use instanceof).

[evant]

Changed back for backwards compat.