add-meeting.html features

- Date & clock picker
- Add invitee
- Basic UNIX conversion from date string
- AJAX form submission
Merge branch 'master' of https://github.com/hamlim/ShirleysScheduler

Conflicts:
	frontend/add-meeting.html
	frontend/js/ss.ajax-pages.js
Merge branch 'master' of https://github.com/hamlim/ShirleysScheduler

Conflicts:
	frontend/add-meeting.html
	frontend/js/ss.ajax-pages.js