Emit error on serialport when explicit handler present. Fixes gh-369

Signed-off-by: Rick Waldron <waldron.rick@gmail.com>
Merge pull request #375 from giseburt/master

Fix for windows and Node 0.11.13 (atom-shell)
Merge pull request #370 from rwaldron/369

Emit error on serialport when explicit handler present. Fixes gh-369
Version 1.4.6 [publish binary]