almost every view created by webix will never be released!
even call ‘destructor’ function still can’t release the view from memory,
because in webix.Destruction’s $init push every view’s reference to webix.destructors, but never remove the view’s reference from webix.destructors.
webix.Destruction’s ‘destructor’ didn’t do this.
so except close the window, you can’t release the view.
webix._events also has the same problem, webix._events will always catch the reference of the view, until the window is closed.