This microcode will not run versions of Edwin prior to 3.66.

This microcode will not run versions of Edwin prior to 3.66.

* Add new primitive WITH-STACK-MARKER that marks the stack for the
  benefit of the continuation parser.

* Implement new set of directory-reading primitives that are
  reentrant.

Changes to X interface:

* Add support for WM_DELETE_WINDOW and WM_TAKE_FOCUS window manager
  protocols.

* Add support for Scheme to receive MapNotify and UnmapNotify events.

* Window creation primitives allow third argument to be (NAME . CLASS)
  meaning set the class hint to those strings.

* Primitive X-WINDOW-SET-CLASS-HINT now takes three arguments instead of
  four; the first argument was redundant.  The last two arguments have
  been reversed.

* New primitive X-WINDOW-SET-INPUT-HINT for use together with
  WM_TAKE_FOCUS protocol.

* New primitives X-WINDOW-SET-TRANSIENT-FOR-HINT, X-WINDOW-ICONIFY,
  and X-WINDOW-WITHDRAW.