Added Libertree.UI.isTouchInterface .
Add touch-interface CSS class to body when touch interface is detected.  Set up CSS classes to hide or show elements based on touch or not.
Make notification age text size match notification text size.
DRY up the notification partials.
DRY up notification view code some more.
Separate notification avatar into its own column (allow no text to flow below it).  CSS repairs to follow.
CSS cleanup in notifications: spacing, margin, padding, etc.
Show glimpses in notifications all the time when viewing with a touch interface.
Notifications: CSS fixes.
Make glimpses safer with Libertree.plain().