PUB-586: more fixes - checking set flag for the field.

If the classification field is not set (i.e., sent by client)
derived it to right value based on type of response column.
Merge branch 'master' of github.com:0xdata/h2o
Merge branch 'master' of github.com:0xdata/h2o
Merge branch 'master' of github.com:0xdata/h2o