Improve demo site

_This is a work-in-progress ticket to track work on Oscar's demo site._

## Background

Oscar ships with a demo site in `sites/demo` that can be deployed to http://demo.oscarcommerce.com/.  At the moment, this site is a skeleton but it should be a custom Oscar projects that shows off its flexibility and extensions.

In light of an upcoming ecommerce expo, the plan is to complete this demo store by the 17th April 2013.  The theme of the demo store will be sailing and will sell a range of different product types, all related to sailing.

## Requirements

- [ ] Custom skin/mark-up that looks significantly different from the sandbox.  Tangent's creative department to help with this.

- A range of different product types:

    - [ ] Books (physical)
    - [ ] PDF downloads (digital)
    - [ ] Clothing (variants)
    - [ ] Banners (customisable)
    - [ ] Holiday bookings (intangible)
    - [ ] Chains/rope (variable pricing) [optional]
    - [ ] Something with access control [optional]

- [ ] A range of different offer types running

- [ ] Search with faceting

- [ ] Merchandised homepage and category homepages

Integrate with the following Oscar extensions:

- [ ] Stores
- [ ] Fancypages
- [ ] Accounts
- [ ] PayPal
- [ ] DataCash

In production settings:

- [ ] Use cached template loading