Homepage changes per marketing/product mgmt

- Adds a banner for an upcoming webinar (still waiting for the link)
- Adds a section for dev tools (apigility, z-ray, studio) above news
- Adds a slide-up pop-in ad for z-ray (with cookie, which prevents display on
  subsequent visits). Required adding ability to inject inline scripts in the
  layout.
Zend Server ad for downloads sidebar
Linked to webinar
Updated homepage based on template
Merge branch 'feature/zend-server-promo'