Add last_modified callback
Add last_modified callback

NineFX/webmachine,i11/webmachine,anish-mp/webmachine,chef/webmachine,abanca/webmachine,cmeiklejohn/webmachine,choptastic/webmachine,Webmachine/webmachine,amerisoft/webmachine,vinoski/webmachine,basho/webmachine,kellymclaughlin/webmachine,mondemand/webmachine,srenatus/webmachine,srenatus/webmachine,voila/webmachine,joedevivo/webmachine,chef/webmachine,rabbitmq/webmachine,basho/webmachine,campanja/webmachine,lemenkov/webmachine,tsloughter/webmachine,kellymclaughlin/webmachine,liuhongchao/webmachine,boundary/webmachine,mondemand/webmachine,spilgames/webmachine,samuelrivas/webmachine,voila/webmachine,kbrown/webmachine,nparry/webmachine,pooya/webmachine,abanca/webmachine,riak-synrc/webmachine,pooya/webmachine,liuhongchao/webmachine,agx/webmachine,zkessin/webmachine,zkessin/webmachine,cmeiklejohn/webmachine,tsloughter/webmachine,Webmachine/webmachine,sdebnath/webmachine,kbrown/webmachine,spilgames/webmachine,sdebnath/webmachine,choptastic/webmachine,joedevivo/webmachine,riak-synrc/webmachine,boundary/webmachine,lemenkov/webmachine,agx/webmachine,campanja/webmachine,rabbitmq/webmachine,anish-mp/webmachine,nparry/webmachine,amerisoft/webmachine,samuelrivas/webmachine,joedevivo/webmachine,i11/webmachine,rabbitmq/webmachine,riak-synrc/webmachine,NineFX/webmachine,vinoski/webmachine