Simplify the set_*_attribute handlers.
Simplify the set_*_attribute handlers.

putneyj/activerecord-userstamp,putneyj/activerecord-userstamp,putneyj/activerecord-userstamp,jparr/activerecord-userstamp,reger/activerecord-userstamp,lowjoel/activerecord-userstamp,reger/activerecord-userstamp,jparr/activerecord-userstamp,lowjoel/activerecord-userstamp,lowjoel/activerecord-userstamp,reger/activerecord-userstamp,jparr/activerecord-userstamp