Added StatGrabberInterface to send UDP messageas to statgrabber
corrected bug: return strings rather than LoginIds for list connected
added startup cache to ServiceWorkers
Improved the interface of FullDuplexConnection. This is the residue  of a failed attempt to recycle buffers with the Leaky Bucket algorithm
Moved FullDuplexConnection into its own package (fdx)
added python style level literals to logging