add $showActions allowing hiding of actionsBlock

to hide 'actions' block:

	$this->set('showActions', false);

in the view.

Fixes #346
avoid adding 'current' class to multiple menu item

eg: navigating to '/admin/settings' would mark all Settings submenus as
current. this change would make only the first item as current.

fixes #345
adding semicolons in admin.js
remove extra <li> tag