Enhancements:
- Performance optimization for both data writing and query
- FILL is supported in stream processing
- interp function can return timestamp
- Add index by default for system builtin tables
- Some columns can't be queried from information_schema.ins_tables
Fixed Bugs:
- Memory leak in TDengine CLI
- The result is different when querying first with or without interval
- Query returns empty data set
- Error result when delete source data of a stream processing
- taosd crash