Add support for multiple instances of the same command

This patch adds support for starting and supervising multiple
services (run, task, or service) using an extra #ID number.

service #1 [2345] /sbin/httpd -f -h /http -p 80   -- Web server
service #2 [2345] /sbin/httpd -f -h /http -p 8080 -- Old web server

Also included in this patch is a fix for endless respawn of faulty
services.  For instance, a buggy daemon that crashes repeatedly will now
be stopped after 10 respawns.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

helpers.h

@@ -103,7 +103,6 @@ int     pid_alive       (pid_t pid);
 char   *pid_get_name    (pid_t pid, char *name, size_t len);
 
 void    procname_set    (char *name, char *args[]);
-int     procname_kill   (char *name, int signo);
 
 void    print           (int action, const char *fmt, ...);
 void    print_desc      (char *action, char *desc);