Add time and calendar settings to date field

See #2002
Create calendar interface

See #2002
Select date from calendar

See #2002
Calendar interactions

See #2002
Highlight active day

See #2002
Add calendar styling and interactions

See #2002
Merge branch 'integration' of github.com:symphonycms/symphony-2 into integration
Calendar improvements

- better element positioning
- focus current date
Calendar documentation
Publish Filtering and Empty Sections

Fixes #2246