otherwise the warning method produced a (deprecation) warning itself ;-)

…-project#310)

most prominently `df.loc[key] = value` and `df.iloc[key] = value` but
also `arr.data[0] = -1` or `arr.data = np.array([[5, 6, 7], [8, 9, 0]])`

…nd display/log errors correctly

…array-project#310)

or any Collection (which must have __len__ and __iter__ methods by definition) but which raise a TypeError when calling them,
such as scalar Groups

…ct#313)

…luding NaN) columns (closes larray-project#311)

…ic (including NaN) columns

… file and display/log errors correctly