TAJO-956: CONCAT should be support multiple params and null param. (Hyoungjun Kim via hyunsik)

 Closes #81
TAJO-960: TajoCli's problem does not show the current status.

Closes #83
TAJO-955: Add database selection submit button in catalogview.jsp for text based browse. (Hyoungjun Kim via jihoon)
TAJO-961: TajoCli should exit when at least one query faces error while executing a SQL script. (hyunsik)

Closes #84