Fix name of Schedule Template

Changed the Wordpress display name from Schedule to Schedule Template
Add registration template and fix some styles

Add a registration template page that calls the TeamData APIs to add a
new member, as well as adding styles for that page.

I also fixed some styles for the 404 not found page so that it doesn't
look like a mess.
Remove stale style block from register template

Remove unnecessary style block from the template.
Use jQuery dialog for messages in registration

Add the use of the jQuery UI dialog widget in the registration template
for messages and errors.
Generalise use of jQuery UI dialog

Move the code for using a modal dialog into mystic.js and make it handle
cases where the jQuery UI dialog component isn't available. Also tweak
the classes as part of making the feature more generic.