
The x64 binaries provided on RXTX download site does not work, 
according to notes on their website, http://rxtx.qbang.org/wiki/index.php/Download. 
Therefore for consistency purposes, all Linux and Windows binaries are downloaded 
from https://code.google.com/p/create-lab-commons/source/browse/trunk/java/lib/rxtx

See their README on build details. 
https://code.google.com/p/create-lab-commons/source/browse/trunk/java/lib/rxtx/README.txt