WS-3000 driver for weewx v0.3

updated for python 3 compatibility
moved the data service to another repository
packaged as an extension

WS-3000 driver for weewx v0.2

Release notes

This is the initial version of the code.
It is not packaged as an extension and must be manually deployed.

It also still includes the data service, which will be moved to its own repository.