init: add logrotate.conf

logrotate was broken due to phusion/baseimage-docker#338
This changes logrotate to use the root user which has the proper
permissions on /var/log.

conf/init/logrotate.conf

@@ -0,0 +1,42 @@
+#
+# This file exists because of a bug in phusion/baseimage:0.9.19 where the su
+# directive below is configured to use the nonexistant syslog user.
+#
+
+
+# see "man logrotate" for details
+# rotate log files weekly
+weekly
+
+# use the syslog group by default, since this is the owning group
+# of /var/log/syslog.
+su root root
+
+# keep 4 weeks worth of backlogs
+rotate 4
+
+# create new (empty) log files after rotating old ones
+create
+
+# uncomment this if you want your log files compressed
+#compress
+
+# packages drop log rotation information into this directory
+include /etc/logrotate.d
+
+# no packages own wtmp, or btmp -- we'll rotate them here
+/var/log/wtmp {
+    missingok
+    monthly
+    create 0664 root utmp
+    rotate 1
+}
+
+/var/log/btmp {
+    missingok
+    monthly
+    create 0660 root utmp
+    rotate 1
+}
+
+# system-specific logs may be configured here