1. Go through dependencies list one round to ensure compliance. Generated current NOTICE list in all submodules (other apache projects like flink does this).
To be on conservative side regarding licensing, NOTICE.txt lists all dependencies including transitive. Pending Compliance questions reported in https://issues.apache.org/jira/browse/LEGAL-461
2. Automate generating NOTICE.txt files to allow future package compliance issues be identified early as part of code-review process.
3. Added NOTICE.txt and LICENSE.txt to all HUDI jars
