defect fix when explicitly setting a second stream for LogFileTee()

fixed typo in LogFileTee implementation.

BREAKING API CHANGE: objects are no longer exported.

The API has been changed to no longer export classes that you create with new, but functions that create the objects for you.
Replace new stee.LogTee([stream1, stream2, stream3]) with stee.createLogTee([stream1, stream2, stream3]).
Replace new stee.LogFileTee('my.log') with stee.createLogFileTee('my.log').

Choose any second stream when teeing to a file

optionally provide a second stream (or null for none) to LogFileTee() - the default is stdout, which matches the behavior from before

In addition to anywhere, you can now tee to nowhere!

Added convenience function teeToNowhere() that sends whatever is written to it nowhere.

now with teeToStdoutOnly()!

Added a convenience function for writing to stdout only.

Working release.

Basic, and that might be all it ever needs to be.