* mailinglist.c, support.c: include <string.h>
* sysoputil.c: include <string.h>, <limits.h>, "config_defs.h", remove
duplicated defs, replace gets() call with fgets()
* mailinglist.c, support.c: include <string.h>
* sysoputil.c: include <string.h>, <limits.h>, "config_defs.h", remove
duplicated defs, replace gets() call with fgets()