patch 7.4.2180

Problem:    There is no easy way to stop all timers.  There is no way to
            temporary pause a timer.
Solution:   Add timer_stopall() and timer_pause().

src/structs.h

@@ -3159,6 +3159,7 @@ struct timer_S
     timer_T	*tr_next;
     timer_T	*tr_prev;
     proftime_T	tr_due;		    /* when the callback is to be invoked */
+    int		tr_paused;	    /* when TRUE callback is not invoked */
     int		tr_repeat;	    /* number of times to repeat, -1 forever */
     long	tr_interval;	    /* msec */
     char_u	*tr_callback;	    /* allocated */