Link imported ProtoDescriptors

Hello @dpup, 

Please review the following commits I made in branch 'nick-imports'.

1145d89d0550b317f4c591ca6c87e188e0bfcf60 (2013-05-16 15:53:02 -0400)
Link imported ProtoDescriptors 
- [ ] The Protos have been reviewed

R=@dpup