Remove modal on watch a demo

Pls review @jamesshedden – removes modal on /watch-a-demo agreed with @MattRobinson today.

I've added a 'contact sales' link in the footer which forwards to our contact form to allow visitors to still easily reach that lead capture.

![screen shot 2014-09-01 at 15 38 36](https://cloud.githubusercontent.com/assets/51724/4109487/acecb4a0-31e5-11e4-9f67-8f8ea6705430.png)