v5.6.4-1.0.2

This is ZomboDB v5.6.4-1.0.2. It's primarily a bugfix release.

Bugs Fixed

• Issue #260: Nested #expand() queries no longer cause the backing Elasticsearch cluster to deadlock
• Issue #261: The SQL function zdb_score() now works in all cases

New Features

• Issue #259: A new query clause called #subselect() has been added.