Optimize partition pruning for Hive client

- replace usage of Warehouse.makeSpecFromName with a more efficient implementation
- build filters based on all partition keys, even if they are missing and call
  getPartitionNamesByParts. Use empty string as placeholder for missing filters
- short-circuit parsing partition key values and creating partition objects if
  we can determine the partition doesn't match the predicate
Add 0.85 release notes
[maven-release-plugin] prepare release 0.85
[maven-release-plugin] prepare for next development iteration
Fix tracking of input rows/bytes for JOIN stages

This is a little hacky, since we should really be tracking
just the inputs due to the TableScan operator for any given
stage. However, the current stats rollup system doesn't
support this.