Add cleanup codes for Emacs daemon

* exwm-floating.el (exwm-floating--exit):
* exwm-input.el (exwm-input--exit):
* exwm-layout.el (exwm-layout--exit):
* exwm-manage.el (exwm-manage--exit):
* exwm-randr.el (exwm-randr--exit):
* exwm-systemtray.el (exwm-systemtray--exit):
* exwm-workspace.el (exwm-workspace--exit):
New functions for cleanup each module.

* exwm-input.el (exwm-input--on-pre-command, exwm-input--on-post-command)
(exwm-input--init): Name lambda functions.

* exwm-layout.el (exwm-layout--timer, exwm-layout--init): Save timer.

* exwm-randr.el (exwm-randr-enable): Register the cleanup function.

* exwm-systemtray.el (exwm-systemtray--init): Force refresh atoms in XEMBED
and system tray protocols.
(exwm-systemtray-enable): Register the cleanup function.

* exwm-workspace.el (exwm-workspace--client): Save the server process.
(exwm-workspace--confirm-kill-emacs): Add emacsclient-specific
cleanup codes.
(exwm-workspace--timer): Save the timer.
(exwm-workspace--init): Save the server process and timer;
fix problems with emacsclient frames.

* exwm.el (exwm-init): Always select the newly created frame;
force refresh ICCCM & EWMH atoms.
(exwm-exit-hook): New hook for holding cleanup codes.
(exwm--exit): Run `exwm-exit-hook', execute cleanup codes for
each module and reset the environment.

exwm-randr.el

@@ -164,9 +164,13 @@
                            ))
         (xcb:flush exwm--connection)))))
 
+(defun exwm-randr--exit ()
+  "Exit the RandR module.")
+
 (defun exwm-randr-enable ()
   "Enable RandR support for EXWM."
-  (add-hook 'exwm-init-hook #'exwm-randr--init))
+  (add-hook 'exwm-init-hook #'exwm-randr--init)
+  (add-hook 'exwm-exit-hook #'exwm-randr--exit))