Log Message:
Update to 0.020

Upstream changes:
0.020           2022-03-17      T. R. Wyant
    Correct and optimize the computation of logical column position (the
    one that takes account of tabs).

0.019           2021-11-15      T. R. Wyant
    Add CONTRIBUTING file.

    Try to quell weird Win32 test failures which seem to occur only in
    tests where I am using 'use open' to put the standard handles into
    UTF-8 mode. The fix (I hope) is to do this to the Test::Harness
    handles at run time instead of to the standard handles at compile
    time.