This commit adds an `anon` class to the html tag when an anonymous user
visits a page. This allows elements to be appropriately hidden through
CSS alone.

The following things have been removed/cleaned up:
 * The `oae-anon-toggle` class for hiding the lhnav toggle
 * JS code related to hiding comment functionality
 * Trimpath code related to hiding comment functionality
 * A reference to the unused class `topnavigation-logged-out`
Added an `oae-hide-when-anonymous` CSS class

When the `oae-hide-when-anonymous` class has been applied on an element
that element will be hidden from anonymous users.
Merge branch 'bootstrap3-anon' of https://github.com/simong/3akai-ux into bootstrap3-anon
Documentation improvements for .anon class