Add Behat behaviours to click links and submit forms in preview.
Merge pull request #3000 from mateusz/preview-behaviours

Add Behat behaviours to click links and submit forms in preview.
BUG Fix Date and SS_DateTime::FormatFromSettings
This issue is caused by the odd default behaviour of Zend_Date, which attempts to parse yyyy-mm-dd format date and times as though they were yyyy-dd-mm.
Merge pull request #3002 from tractorcow/pulls/3.1-datetime-fix

BUG Fix issue with SS_DateTime::FormatFromSettings failing to parse dates
Update datefield.md

Removed ; at the end of ->setConfig('dmyfields', true) in the three chain example. Is confusing for new users/developers who are not aware of how to chain methods.

Closes #3006