A couple bugs with getModel() method

[jacobg]

In getModel() method:

1. The call to Ext.ModelManager.get should be Ext.ModelManager.getModel.

2. It defines SlideNavigationPanelItem model class as a global variable via Ext.define. That is bad practice to pollute the global namespace. A better way to set the model name would be like this:

var className = this.self.getName(),
    model = className.substr(0, className.lastIndexOf('.')) + '.SlideNavigationPanelItem';