i2prouter: set locale environment variables if LANG not set

Check for /etc/environment and /etc/default/locale and retrieve/set locale
variables from them--but only if LANG is unset. This should help in those
cases in which someone is starting I2P as a daemon using an initscript and I2P is
starting /before/ the environment is configured, leading to the wrong file
encoding being detected.

installer/resources/i2prouter

@@ -107,6 +107,22 @@ WAIT_FOR_STARTED_TIMEOUT=120
 # flag for using upstart when installing (rather than init.d rc.d)
 USE_UPSTART=
 
+# Source the environment variables for the locale if $LANG isn't set
+# If you want to set custom locale variables for I2P,
+# you may comment out this block and set them yourself here.
+
+if [ ! -n $LANG ]; then
+        for ENV_FILE in /etc/environment /etc/default/locale; do
+                [ -r "$ENV_FILE" ] || continue
+                [ -s "$ENV_FILE" ] || continue
+
+                for var in LANG LANGUAGE LC_ALL LC_CTYPE; do
+                        value=`egrep "^${var}=" "$ENV_FILE" | tail -n1 | cut -d= -f2`
+                        [ -n "$value" ] && eval export $var=$value
+                done
+        done
+fi
+
 # When installing on On Mac OSX platforms, the following domain will be used to
 #  prefix the plist file name.
 PLIST_DOMAIN=org.tanukisoftware.wrapper