An XMPP stream is essentially a long-running XML document. As such, an XMPP stream often is preceeded with an XML declaration (eg: `<?xml version="1.0" encoding="UTF-8"?>`).

The inclusion of this XML declaration in streams that are started by Openfire should be made configurable. Additionally, if such declaration is used, wether or not it should be followed by a newline should be made configurable.

The latter can be useful to work around client issues, eg: