Account for missing values in column type determination.
Account for missing values in column type determination.

If no values exist for a column, the default column type is 'Text'.

IljaZakharov/benchexec,dbeyer/benchexec,sosy-lab/benchexec,IljaZakharov/benchexec,dbeyer/benchexec,martin-neuhaeusser/benchexec,ultimate-pa/benchexec,ultimate-pa/benchexec,ultimate-pa/benchexec,dbeyer/benchexec,martin-neuhaeusser/benchexec,martin-neuhaeusser/benchexec,sosy-lab/benchexec,sosy-lab/benchexec,sosy-lab/benchexec,IljaZakharov/benchexec,IljaZakharov/benchexec,ultimate-pa/benchexec,ultimate-pa/benchexec,dbeyer/benchexec,ultimate-pa/benchexec,sosy-lab/benchexec,martin-neuhaeusser/benchexec,sosy-lab/benchexec