This API takes input XML input in following form.
```
<?xml version="1.0" encoding="UTF-8"?>
<Delete>
<Quiet>true</Quiet>
<Object>
<Key>Key</Key>
</Object>
<Object>
<Key>Key</Key>
</Object>
...
</Delete>
```
and responds the list of successful deletes, list of errors
for all the deleted objects.
```
<?xml version="1.0" encoding="UTF-8"?>
<DeleteResult xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
<Deleted>
<Key>sample1.txt</Key>
</Deleted>
<Error>
<Key>sample2.txt</Key>
<Code>AccessDenied</Code>
<Message>Access Denied</Message>
</Error>
</DeleteResult>
```
Fail createObject() if a file already exists and one attempts
to create a prefix/directory by same name.
Send an approriate error back to the client as 409 Conflict.
