nightly status checks could fail if any domains had non-ASCII characters

https://discourse.mailinabox.email/t/status-check-emails-empty-after-upgrading-to-v0-16/1082/3

A user on that thread suggests an alternate solution, adding `PYTHONIOENCODING=utf-8` to `/etc/environment`. Python docs say that affects stdin/out/err. But we also use these environment variables elsewhere to ensure that config files we read/write are opened with UTF8 too. Maybe all that can be simplified too.

CHANGELOG.md

@@ -8,6 +8,7 @@ In Development
 * On multi-homed machines, Postfix now binds to the right network interface when sending outbound mail so that SPF checks on the receiving end will pass.
 * Backup times were displayed with the wrong time zone.
 * On low-usage systems, don't hold backups for quite so long by taking a full backup more often.
+* Nightly status checks might fail if any domains had non-ASCII characters.
 
 v0.16 (January 30, 2016)
 ------------------------

conf/management-initscript

@@ -27,9 +27,9 @@ EXEC_AS_USER=root
 
 # Ensure Python reads/writes files in UTF-8. If the machine
 # triggers some other locale in Python, like ASCII encoding,
-# Python may not be able to read/write files. Here and in
+# Python may not be able to read/write files. Set also
 # setup/start.sh (where the locale is also installed if not
-# already present).
+# already present) and management/daily_tasks.sh.
 export LANGUAGE=en_US.UTF-8
 export LC_ALL=en_US.UTF-8
 export LANG=en_US.UTF-8

management/daily_tasks.sh

 #!/bin/bash
 # This script is run daily (at 3am each night).
 
+# Set character encoding flags to ensure that any non-ASCII
+# characters don't cause problems. See setup/start.sh and
+# the management daemon startup script.
+export LANGUAGE=en_US.UTF-8
+export LC_ALL=en_US.UTF-8
+export LANG=en_US.UTF-8
+export LC_TYPE=en_US.UTF-8
+
 # Take a backup.
 management/backup.py | management/email_administrator.py "Backup Status"
 

setup/start.sh

@@ -10,8 +10,8 @@ source setup/preflight.sh
 
 # Ensure Python reads/writes files in UTF-8. If the machine
 # triggers some other locale in Python, like ASCII encoding,
-# Python may not be able to read/write files. Here and in
-# the management daemon startup script.
+# Python may not be able to read/write files. This is also
+# in the management daemon startup script and the cron script.
 
 if [ -z `locale -a | grep en_US.utf8` ]; then
     # Generate locale if not exists