Online demo for KA Lite: show demo info, prevent access to the Django admin.

Title says it all.  Here's some screen shots:

Homepage tells instructions and credentials 
![screen shot 2014-02-27 at 1 14 51 pm](https://f.cloud.github.com/assets/4072455/2287989/4225e94e-9ff4-11e3-8698-b0b8d028913f.png)

When user isn't logged in, they are given options for credentials.
![screen shot 2014-02-27 at 1 14 56 pm](https://f.cloud.github.com/assets/4072455/2287988/3fad5742-9ff4-11e3-802a-89c3889ef011.png)

If user tries to access django admin, they get this:
![screen shot 2014-02-27 at 1 05 25 pm](https://f.cloud.github.com/assets/4072455/2287927/345a9f04-9ff3-11e3-95d6-ed0f181fd574.png)