Catching and displaying more error on SparkSql
Make SparkInterpreter and SparkSqlInterpreter uses the same scheduler instance
Handling null, empty line interpret
Merge pull request #103 from NFLabs/catching_more_error_on_sparksql

Catching and displaying more error on SparkSql
Merge pull request #104 from NFLabs/scheduler_refactoring

Run sequentially all Spark/SparkSql paragraph when 'Run' button pressed