- Initial implementation of Help command.
- Simplified Record to use Tuple as internal data storage and removed unnecessary operator overloads.
- Created initial definition of the ExecutionStep class.
- Changed Engine to build execution plan instead of executing commands immediately.
- Extracted logic for preparing an execution plan from the Engine class into a new ExecutionPlan class.
- Changed CommandMetadata to return empty enumerables to eliminate special handling in consuming code.
- Extended Engine and ExecutionPlan to log reason why a command is being executed.