Task: Use dates instead of datetimes when setting fields in ActionSucceeded subscribers.

`expectedStartOfWork` and `date_of_completion` are Date fields, not DateTime.
And so are the corresponding columns in SQL.
Merge pull request #555 from 4teamwork/lg-use-dates-in-task-wf-change-subscribers

Task: Use dates instead of datetimes when setting fields in ActionSucceeded subscribers.
Improve DB-schema migration robustness.

A migration should now be able to resume in some more cases after a
previously failed upgrade.
Fix indentation for development-packages.
Merge pull request #554 from 4teamwork/deif-migration-robustness

Improve DB-schema migration robustness.
Update doc-properties when moving/copying documents.
Update DocProperties after document checkin/checkout.
Create journal entry when updating/adding doc properties.
Remove duplicate readme entries, improve readability.
Update history.