Cardano Clusterlib 0.4.0

Version 0.4.0 breaks compatibility with 0.3.0.

There was a large number of unorganized methods that made usage of the library difficult. In 0.4.0 the methods are organized into functionality groups. Each group is prefixed with g_. The group names mimics cardano-cli.

For example, instead of cluster.get_tip() we now have cluster.g_query.get_tip().

There is a sed script that might help with refactoring to 0.4.0 methods organization.