* Allow explicit inclusion of session tags in the SDK, enabling the
resending of tags bundled with messages that would not otherwise
be ACKed.
* Don't force mode=guaranteed for end to end delivery - if mode=bestEffort
no DeliveryStatusMessage will be bundled (and as such, client apps using
it will need to do their own session tag ack/nack).
* Handle client errors when notifying them of message availability.
* New StreamSinkSend which sends a file to a destination and disconnects.
* Update the I2PSocketManagerFactory to build the specific
I2PSocketManager instance based on the "i2p.streaming.manager" property,
containing the class name of the I2PSocketManager implementation to instantiate.