Allow Trait API clients to override and use initlialize method of TraitView class

Current behaviour: When traits get added with TraitView.addType method they are extend TraitsViewer.itemView(which is TraitView). When TraitSelectView class extends TraitView it overrides initialize(o) method and calls TraitView.prototype.initialize.apply(this, arguments); to initialize parent class(as i understand). This allows TraitSelectView to override some initializing logic. For example override this.tmpl and use custom template for a trait For a custom trait with overridden initialize method there we gonna see an error: But with the following code everything works perfect and i can ove...