crtools: make to be able to split messages by pid

If the option --log-pid is set, each process will have an own log file.
Otherwise PID is added to each log message.

A message can't be bigger than one page minus some bytes for pid.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/crtools.h

@@ -74,6 +74,8 @@ struct cr_options {
 	bool			ext_unix_sk;
 	bool			tcp_established_ok;
 	unsigned int		namespaces_flags;
+	bool			log_file_per_pid;
+	char			*output;
 };
 
 extern struct cr_options opts;