TAJO-786: TajoDataMetaDatabase::getSchemas creates invalid MetaDataTuple.
TAJO-783: Remove yarn-related code from tajo-core. (hyunsik)
TAJO-787: FilterPushDownRule::visitSubQuery does not consider aliased columns. (jaehwa)
TAJO-788: Update Tajo documentation and README, and BUILDING. (hyunsik)