#### Bug, feature request, or proposal: Feature request: migrate/implement attribute md-prevent-menu-close from AngularJS to material2. #### What is the expected behavior? When user uses md-prevent-menu-close attribute, after choosing an item - menu should not close. #### What is the current behavior? There is no md-prevent-menu-close and when user clicks menu items, the menu disappears; event.stopPropagation() or event.preventDefault do not work.