bunch of new DataSet methods: rename(), vmerge(), recode(), slicer(), fill_conditional(), derive_categorical(). name change: add_var_meta() --> add_meta()
bunch of new DataSet methods: rename(), vmerge(), recode(), slicer(), fill_conditional(), derive_categorical(). name change: add_var_meta() --> add_meta()

Quantipy/quantipy,Quantipy/quantipy,Quantipy/quantipy,Quantipy/quantipy