desired GWData enhancements

[cwipf]

• Windows support
• Use nds2-client iterate() rather than fetch() so testpoint data can be read
• Less clunky way of dealing with the list of servers (use a Map object instead?)
• Method for obtaining channel lists and/or live connection objects

[cwipf]

Beginnings of Windows support: 80882d33aa37b4c29d4707045286f669a325586e

[cwipf]

• Also, if nds2-client was added to Matlab's path, we should still check it against nds-client-config, and warn if they don't match.