Fix compile errors and test failures in UDT mapping.
Merge pull request #196 from olim7t/fix_mapper

Fix compile errors and test failures in UDT mapping.
Update 'upgrade guide' for 2.1
Merge commit '2c316608e923fc9f93b689aaf726b43d87abe923' into 361v2
Merge branch '361v2' into integration-151-361v2