[Bug 1187070] Don't use repr for Documents in DocumentLink.
[Bug 1187070] Don't use repr for Documents in DocumentLink.

I'm not sure why, but this causes some Django templates to get very
confused and throw unicode decode errors. In particular, when trying to
delete documents, if the document is linked to another document and one
of those two documents has unicode in the title, the '%r' in the format
string throws an error. Changing these to %s fixes the delete page.

I still don't know what is going on here. I tried and failed to
reproduce it.

iDTLabssl/kitsune,turtleloveshoes/kitsune,mozilla/kitsune,NewPresident1/kitsune,asdofindia/kitsune,MziRintu/kitsune,asdofindia/kitsune,YOTOV-LIMITED/kitsune,mozilla/kitsune,H1ghT0p/kitsune,asdofindia/kitsune,MikkCZ/kitsune,iDTLabssl/kitsune,brittanystoroz/kitsune,mythmon/kitsune,brittanystoroz/kitsune,H1ghT0p/kitsune,H1ghT0p/kitsune,H1ghT0p/kitsune,feer56/Kitsune2,turtleloveshoes/kitsune,MziRintu/kitsune,feer56/Kitsune2,anushbmx/kitsune,mythmon/kitsune,mozilla/kitsune,turtleloveshoes/kitsune,YOTOV-LIMITED/kitsune,MziRintu/kitsune,brittanystoroz/kitsune,safwanrahman/kitsune,iDTLabssl/kitsune,MikkCZ/kitsune,chirilo/kitsune,chirilo/kitsune,MikkCZ/kitsune,Osmose/kitsune,mozilla/kitsune,silentbob73/kitsune,safwanrahman/kitsune,mythmon/kitsune,chirilo/kitsune,iDTLabssl/kitsune,NewPresident1/kitsune,anushbmx/kitsune,feer56/Kitsune2,safwanrahman/kitsune,NewPresident1/kitsune,chirilo/kitsune,silentbob73/kitsune,safwanrahman/kitsune,asdofindia/kitsune,feer56/Kitsune2,MikkCZ/kitsune,YOTOV-LIMITED/kitsune,Osmose/kitsune,Osmose/kitsune,mythmon/kitsune,YOTOV-LIMITED/kitsune,anushbmx/kitsune,anushbmx/kitsune,MziRintu/kitsune,silentbob73/kitsune,turtleloveshoes/kitsune,brittanystoroz/kitsune,NewPresident1/kitsune,Osmose/kitsune,silentbob73/kitsune