Add documentation for JDBC driver
Add 0.57 release notes
Update snapshot dependencies
[maven-release-plugin] prepare release 0.57
[maven-release-plugin] prepare for next development iteration
Fix formatting and optimize imports
Fix variable naming
Make utility classes final with private constructor
Add Checkstyle configuration
Fix a bunch of formatting errors
Fix warnings in Hive file format tests
UDF supports as a internal plugin
Remove group field at Signature