updated for version 7.4.138
Problem:    Directory change messages are not recognized.
Solution:   Fix using a character range literally. (Lech Lorens)
Added tag v7-4-138 for changeset 6eb60041548c
updated for version 7.4.139
Problem:    Crash when using :cd in autocommand. (François Ingelrest)
Solution:   Set w_localdir to NULL after freeing it. (Dominique Pelle)
Added tag v7-4-139 for changeset c8c80c9d2e22