v0.19.2

New features

• added disallowmissing, allowmissing and categorical functions
• unstack now accepts renamecols keyword argument

Minor changes

• documentation has been updated to reflect new indexing rules
• setindex! deprecation warnings were improved and now take into account new rules of broadcasting into 0-row data frames
• :eltype column in describe now contains a true element type of a data frame column (previously if the type was an union with Missing then the Missing part was stripped, which sometimes lead to user confusion)
• broadcasting over GroupedDataFrame is now disallowed (it was never intended to work; in the future this might be allowed, but the target design is not decided upon yet)
• append! now throws ArgumentError instead of ErrorException when column names of appended data frame does not match the target

Bug fixes

• fixed a typo in append! error message
• fixed a bug in categorical! function when a Colon as column selector was passed (the behavior was inconsistent with the documentation); now only categorical!(::DataFrame) changes columns whose eltype is <:Union{AbstractString, Missing} to categorical; any valid categorical!(::DataFrame, cols) call changes all columns selected by cols to categorical