Merge pull request #284 from trevorbernard/master

Fix issue #283 - Add libsodium to travis-ci build
Add the ZMQ_CONFLATE option.
Merge pull request #288 from GreatFruitOmsk/master

Add the ZMQ_CONFLATE option.
fix jni getLongSockopt
Merge pull request #289 from ealgell/fix-285

fix jni getLongSockopt
Fix regression with issue #283