Add support for logging exit status events.

For sudo-formatted logs, this is a record with "EXIT=number" and
potentially "SIGNAL=name" after the command.  For JSON-format logs,
a new "exit" record is logged which contains an "exit_value" and
potentially "signal" and "core_dumped".  JSON-format logs now incude
a UUID to associate the "exit" record with the "accept" record.

include/sudo_eventlog.h

@@ -31,6 +31,7 @@
 enum event_type {
     EVLOG_ACCEPT,
     EVLOG_REJECT,
+    EVLOG_EXIT,
     EVLOG_ALERT
 };
 
@@ -122,6 +123,7 @@ struct json_container;
 typedef bool (*eventlog_json_callback_t)(struct json_container *, void *);
 
 bool eventlog_accept(const struct eventlog *evlog, int flags, eventlog_json_callback_t info_cb, void *info);
+bool eventlog_exit(const struct eventlog *evlog, int flags, struct timespec *run_time, int exit_value, const char *signal_name, bool core_dumped, eventlog_json_callback_t info_cb, void *info);
 bool eventlog_alert(const struct eventlog *evlog, int flags, struct timespec *alert_time, const char *reason, const char *errstr);
 bool eventlog_reject(const struct eventlog *evlog, int flags, const char *reason, eventlog_json_callback_t info_cb, void *info);
 bool eventlog_store_json(struct json_container *json, const struct eventlog *evlog);