Dockerfile modified for adding Jna to jre libraries

Change-Id: Ib44729734428a6895b96c2461e78ee5bc1de454a
Java class for testing Jna in Docker's container

Change-Id: Iacb53ce7a564b84923fb6a8ead72e539508ad82d
Download jna.jar before deleting curl
README.md modified for adding documentation of JNA

Change-Id: I95051bbb98540e45b29a7633904c4bff922ac775
Merge pull request #1 from rezarahimi/feature/enable_jna

Merge Reza's enable_jna branch