Nullables - why? and how?

[Tamas_Papp]

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DataFrames 0.11 released

After a long and complex development period, we are glad to announce that version 0.11.0 of DataFrames has been released. Among other features listed in the release notes, the major change introduced by this version is the move from the NA value (from the DataArrays package) to the new missing value (from the Missings package, and soon in Base). DataFrames have been completely decoupled from DataArrays: the DataFrame constructor will no longer convert columns to DataArrays, but will keep them a…