[General] Download Pages for OSCON

[Mimi Yin]

In today's Preview Release meeting, we decided to update the  
Downloads pages for Desktop and Server so that people who learn about  
the upcoming Preview Release at OSCON or through OSCON-related blog  
posts don't accidentally download Alpha5 Desktop and 0.6.1 Chandler  
Server and think that's Preview.

I'm adding a message at the top of the page saying that the Preview  
Release is coming soon and to please help us test in the meantime.

http://chandlerproject.org/Projects/DownloadChandlerDesktop
We're pointing Desktop downloaders to the latest checkpoint build.

http://chandlerproject.org/Developers/DownloadChandlerServer
There's an open issue about what to point Server downloaders to,  
qacosmo? Bobby expressed concern about misleading people into  
thinking they can trust real data on qacosmo.

We could add a disclaimer to the effect of: We don't recommend  
trusting qacosmo with your data. Please test with sample data.

Note: This is just an interim solution until we release Preview.

Any concerns with pointing server downloaders to qacosmo to help us  
test?

Mimi