[Design] [cosmo] Update on 0.7 spec

[Priscilla Chung]

I made some updates on the 0.7 spec.

+ Added 'Dashboard for Casual Collaborator' section based on the  
simplified proposal: http://wiki.osafoundation.org/Projects/ 
CosmoZeroDotSevenSpec#DashboardCC
+ Added content in the performance test for QA: http:// 
wiki.osafoundation.org/Projects/CosmoZeroDotSevenSpec#PerformanceTesting

I'm still chipping away at the spec, so comments/suggestions are  
welcome! ;)
Cheers, -Priscilla