Add imapsync tool to Dovecot and change container layout

data/Dockerfiles/dovecot/supervisord.conf

@@ -0,0 +1,21 @@
+[supervisord]
+nodaemon=true
+
+[program:syslog-ng]
+command=/usr/sbin/syslog-ng --foreground --no-caps
+redirect_stderr=true
+autostart=true
+stdout_syslog=true
+
+[program:dovecot]
+command=/usr/sbin/dovecot -F
+autorestart=true
+
+[program:logfiles]
+command=/usr/bin/tail -f /var/log/mail.log /var/log/syslog
+stdout_logfile=/dev/fd/1
+stdout_logfile_maxbytes=0
+
+[program:cron]
+command=/usr/sbin/cron -f
+autorestart=true