scm: view: add #to_s to changeset.author (#5501)
On Ruby 1.8.6, following error raises.
undefined method `mb_chars' for #<ActiveRecord::Associations::BelongsToAssociation:0x7f86950f3e58>
Authored by: tmaruyama 2011-10-21
Parent: [r7638]
Child: [r7640]
