Error messages should not have periods

At least some of them.  For example:

From AWS:
```
<?xml version="1.0" encoding="UTF-8"?>
<Error><Code>NoSuchBucket</Code><Message>The specified bucket does not exist</Message><BucketName>totallymadeupwer3</BucketName><RequestId>F01609D2FA7999DC</RequestId><HostId>s10elYCsWc4AQtNuhXcD7L/3pJfJCHZhmiQQWKs/E5IGZwE8HniZvQFkqsg2AvIsnWKYyibYnH4=</HostId></Error>
```

