Set context class loader when creating ORC writer

The ORC memory manager ends up loading VersionInfo which loads classes
from the context class loader. The tests now set an empty class loader
to verify that it uses the correct class loader.
Add favicon for UI
Add scheduled flag to query info
Only show progress in UI when scheduled
Improve error message for scalar subqueries in groupby
Remove duplicate helper functions in test
Fix formatting for tests
Render byte arrays in the CLI as a hex dump
Improve error message for window functions without an OVER clause
Fix static import warning in PrestoS3FileSystem
Configure MaxRetryTime in PrestoS3FileSystem
Update 0.80 release notes
Add 0.80 release notes
Enable optimized readers by default
Disable new RcFileReader until GC issues are resolved
Fix cassandra timestamp type (from bigint to timestamp)
Change test to expect optimized readers enabled
Update release notes