allow roles to be set for various menu parts

allows the user to set roles and tabindex where appropriate

closes #2

Conflicts:
	dist/main.amd.js
	dist/main.js
	lib/components/ic-menu-item.js
	lib/components/ic-menu-list.js
	lib/components/ic-menu-trigger.js
	lib/components/ic-menu.js
	test/app/templates.js