Sort out event handlers for sliding menu

Instead of tracking the open state of the menu,
use the "slide" class to determine whether the
menu is open or not at the moment. Also, just
switch handlers to one-time-only handlers
each time the menu is clicked.

In addition, use setTimeout() to call
$('#home_page').show(); this ensures that
all layout operations for hidden elements are
completed before attempting to show the home page.