Update to use jeromq 0.3.2

From ChangeLog:
- Various code improvements
- Update junit to version 4.11
- Expose all Context options
- XPUB can receive multipart messages
- Make ZMQ.Context and ZMQ.Socket implement java.io.Closeable
- Use UTF-8 as default charset - fixes #64
- Use monotonic source for time
- Use try finally idiom on locks
- Backport fix for race condition on shutdown
- sendByteBuffer should return number of sent bytes