Various fixes and pubsub

• Fix bugs in dag command
• Support https usage
• implement pubsub

Support ipfs v0.4.11

v1.2.0

update version

Maven fixes

Maven related fixes

Support IPFS v0.4.10

Update to support IPFS version 0.4.10.
This includes adding key management calls.

Support maven

Change package structure to support maven, including dependencies.

Implemented missing add subtree functionality

Updated IPFS.add to support recursively adding a directory subtree.

IPFS 0.4.3 compatible

Reduced minimum ipfs version to 0.4.3

Updated to latest IPFS api

This requires Java 8.

Moved to Maven directory and package structure

v0.4.1

Reinstated Makefile so we don't force people to use maven.

Accessibility corrections.

Corrected accessibility for IPFS inner classes.