Use a Maven properties file

Change-Id: Ic26a63a29ed12cf27c1393defefc1c02eeac1746
Signed-off-by: John May <john.wilkinsonmay@gmail.com>
Restored some error messages

Change-Id: If23acef5f7fa19b868d75c41f604819afe872d18
Signed-off-by: John May <john.wilkinsonmay@gmail.com>