Add configuration option for exchange max response size
Remove unnecessary downcast in AbstractVariableWidthRandomAccessBlock
Reconnect Cassandra session on disconnect

If, for some reason, all hosts become unavailable, we should
re-establish a connection using the original contact points.

In cases where a Cassandra node goes down or moves to a different host,
Presto just keeps throwing NoHostAvailableException until the end of
time.
Format cassandra collection types as JSON

By formatting collection types as JSON, we can use Presto's JSON
functions to extract values.
Fix memory (reservation) leak in PipelineContext
Reduce default memory reservation for DistinctLimitOperator
Include groupAddress in GroupByHash memory usage
Respect max block size in PageBuilder
Reduce memory usage of GroupByHash

Previously memory usage was proportional to the size of the input pages,
and the number of distinct groups. Now it's only dependent on the number
of distinct groups