Fix issue where custom processors are not loaded in Rails 3
Fix issue where custom processors are not loaded in Rails 3

In Rails 3, Paperclip gem being loaded before the Rails object is properly configured and causing those processors not get require'd. This patch should fix that by lazy-loaded the processor.

Closes #206, #233, #247, #480, #494
pandamako/paperclip,pcorliss/paperclip,greatbody/paperclip,victorngkp/paperclip,soramugi/paperclip,freeslugs/paperclip,frankpinto/paperclip,best-teacher/paperclip-old,dgynn/paperclip,12spokes/paperclip,soramugi/paperclip,tylerwillingham/paperclip,InesCARodrigues/paperclip,sopheak-se/paperclip,zurb/paperclip,gfvcastro/paperclip,jonathandean/paperclip_tod,Leadformance/paperclip,tiegz/paperclip,degica/paperclip,degica/paperclip,gfvcastro/paperclip,raow/paperclip,sideci-sample/sideci-sample-paperclip,Cohealo/paperclip,aditya01933/paperclip,joshisa/paperclip,manorie/paperclip,alexandrz/paperclip,felipemathies/paperclip,alexandrz/paperclip,rpbaptist/paperclip,betesh/paperclip,mehulkar/paperclip,felipemathies/paperclip,Flameeyes/paperclip,maintux/paperclip,hooroo/paperclip,manorie/paperclip,carnivalmobile/paperclip,mehulkar/paperclip,agcantarelli/paperclip,betesh/paperclip,justanshulsharma/paperclip,medcat/paperclip,mrgilman/paperclip,joshisa/paperclip,maintux/paperclip,onursarikaya/paperclip,danielwanja/paperclip,mrgilman/paperclip,InesCARodrigues/paperclip,agcantarelli/paperclip,pandamako/paperclip,yukas/paperclip,ScotterC/paperclip,victorngkp/paperclip,ScotterC/paperclip,justanshulsharma/paperclip,mdkalish/paperclip,Cohealo/paperclip,aditya01933/paperclip,cmaion/paperclip,Sporky023/paperclip,bdewater/paperclip,tylerwillingham/paperclip,crowdtap/paperclip,kerrizor/paperclip,rpbaptist/paperclip,Leadformance/paperclip,greatbody/paperclip,keathley/paperclip,freeslugs/paperclip,howaboutwe/paperclip,crowdtap/paperclip,mrb/paperclip,cmaion/paperclip,mdkalish/paperclip,zurb/paperclip,bdewater/paperclip,sopheak-se/paperclip,medcat/paperclip,Sporky023/paperclip,raow/paperclip,frankpinto/paperclip,mrb/paperclip,tiegz/paperclip,onursarikaya/paperclip,keathley/paperclip,carnivalmobile/paperclip,dgynn/paperclip,fxposter/paperclip