Add app promo to all pages

Use SSI
enable SSI on vagrant
we should be refactoring more code
Merge branch 'registration-sponsors+virtual-only'

Conflicts:
	.htaccess
	css/screen.css
	puppet/modules/apache/manifests/init.pp
	register/index.html
	sass/screen.sass
Change the app banner's dismiss button to "Got it".
- Changed the cookie expiration to 365 days
Corrected to "Virtual Attendees" from "Virtual Attendants"