Fix a bug causing us to open a TCP connection to every server and use the last one.

Documentation cleanup.

Code cleanup: Renamed the Version constant. Moved the unique-ID generator into its own file.

Closing this branch.

gofmt

Put the sub-elements of Message and Presence into the jabber:client namespace.

Updated for the latest revision of the encoding/xml fixes: The context object owned by Encoder and Decoder isn't directly accessible. Also improved the output from the two assert functions to show the info of the caller rather than the assert function itself.