Force date format to be same as javascript datepicker

Fixes #514

Signed-off-by: Michal Čihař <michal@cihar.com>
Merge branch 'master' into bootstrap

Signed-off-by: Michal Čihař <michal@cihar.com>

Conflicts:
	weblate/trans/forms.py
Update todo

Signed-off-by: Michal Čihař <michal@cihar.com>