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-floating.el

@@ -622,6 +622,9 @@ Both DELTA-X and DELTA-Y default to 1.  This command should be bound locally."
         exwm-floating--cursor-left
         (xcb:cursor:load-cursor exwm--connection "left_side")))
 
+(defun exwm-floating--exit ()
+  "Exit the floating module.")
+
 
 
 (provide 'exwm-floating)