2010-04-04 John Wiegley <jwiegley@gmail.com>

2010-04-04  John Wiegley  <jwiegley@gmail.com>

	* ido.el (ido-use-virtual-buffers): New variable to indicate
	whether "virtual buffer" support is enabled for IDO.  Essentially
	it works as follows: Say you are visiting a file and the buffer
	gets cleaned up by mignight.el.  Later, you want to switch to that
	buffer, but find it's no longer open.  With virtual buffers
	enabled, the buffer name stays in the buffer list (using the
	ido-virtual face, and always at the end), and if you select it, it
	opens the file back up again.  This allows you to think less about
	whether recently opened files are still open or not.  Most of the
	time you can quit Emacs, restart, and then switch to a file buffer
	that was previously open as if it still were.  NOTE: This feature
	has been present in iswitchb for several years now, and I'm
	porting the same logic to IDO.
	(ido-virtual): Face used to indicate virtual buffers in the list.
	(ido-buffer-internal): If a buffer is chosen, and no such buffer
	exists, but a virtual buffer of that name does (which would be why
	it was in the list), recreate the buffer by reopening the file.
	(ido-make-buffer-list): If virtual buffers are being used, call
	`ido-add-virtual-buffers-to-list' before the make list hook.
	(ido-virtual-buffers): New variable which contains a copy of the
	current contents of the `recentf-list', albeit pared down for the
	sake of speed, and with proper faces applied.
	(ido-add-virtual-buffers-to-list): Using the `recentf-list',
	create a list of "virtual buffers" to present to the user in
	addition to the currently open set.  Note that this logic could
	get rather slow if that list is too large.  With the default
	`recentf-max-saved-items' of 200, there is little speed penalty.