Merge: timer.el: Use time-date fns rather than rolling our own.

This is simpler and helps future-proof the code.
* emacs-lisp/timer.el (timer-until): Use time-subtract and float-time.
(timer--time-less-p): Use time-less-p.

diff --cc lisp/ChangeLog
index 93cf3c4,d137c33..b5d9005
--- 1/lisp/ChangeLog
--- 2/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@@ -1,3 -1,8 +1,10 @@@
 -      * emacs-lisp/timer.el (timer-until): Use time-subtract and float-time.
+ 2011-07-04  Paul Eggert  <eggert@cs.ucla.edu>
+ 
++      * emacs-lisp/timer.el: Use time-date fns rather than rolling our own.
++      This is simpler and helps future-proof the code.
++      (timer-until): Use time-subtract and float-time.
+       (timer--time-less-p): Use time-less-p.
+ 
  2011-07-04  Juanma Barranquero  <lekktu@gmail.com>
  
        * type-break.el (timep): Use the value of `float-time' to avoid a