Tail node and corresponding tests don't work on Windows

There's a comment associated with the tail node saying "Linux and windows only". Would be nice if possible to make this work for Windows.

Also, the corresponding unit test fails on Windows, not only because the actual functionality doesn't work, but because there's a timing window where we look to write to the test file but the file does't exist. This has been seen once or twice on the Travis build. Note that the test uses

fs.unlinkSync(fileToTail);

which on linux deletes the file but on windows only deletes when the running process completes.

Inspect the tail node implementation and its corresponding unit test, starting with the fs.unlinkSync(fileToTail) cleanup described in the issue. Run the test on Windows and compare the tail-node behavior with Linux. Done means the node works on Windows and the test no longer depends on the file-existence timing window.