Change date display in preparation for date logic.
Work date displays into syllabus.
Add back class numbers to syllabus under 'week' heading.
Retab syllabus table.
Replace mako with syllabus YAML
Remove auto margin from p tags in syllabus.
Hooray for functions! Hooray for templates!
Remove superfluous 'topics' list from extras.
Show a date if there is one in extras. Also widen the column.
Add SFD date.