Improve changes#rollback_to redirection.
Improve changes#rollback_to redirection.

* Rolling back a "create" now redirects back to the listing, rather than trying to show the deleted event.
* Added flash message explaining rollback.
* Removed unnecessary `return`.

matthewkmayer/calagator,oktober/calagator,CorainChicago/ActivateHub,iamBalaji/Calagator,shawnacscott/calagator,shawnacscott/calagator,alexbeeken/calagator.org,Villag/dentonator,Villag/dentonator,shawnacscott/calagator,eeeeeean/windchimes,L2-D2/calagator,kerrizor/calagator,reidab/calagator,oktober/calagator,eeeeeean/windchimes,Villag/dentonator,jmcduffie32/calagator,Eugator-Wranglers/calagator,nblackburn87/calagator,bencornelis/calagator,iamBalaji/Calagator,reidab/calagator,matthewkmayer/calagator,jmcduffie32/calagator,L2-D2/calagator,CorainChicago/ActivateHub,iamBalaji/Calagator,dudleysr/calagator-workspace,oktober/calagator,CorainChicago/ActivateHub,nblackburn87/calagator,jmcduffie32/calagator,Eugator-Wranglers/calagator,cp/calagator-1,bencornelis/calagator,iamBalaji/Calagator,matthewkmayer/calagator,VolunteerOdyssey/calagator,jmcduffie32/calagator,VolunteerOdyssey/calagator,shawnacscott/calagator,cp/calagator-1,bencornelis/calagator,dudleysr/calagator-workspace,oktober/calagator,L2-D2/calagator,L2-D2/calagator,bencornelis/calagator,VolunteerOdyssey/calagator,matthewkmayer/calagator,cp/calagator-1,kerrizor/calagator,reidab/calagator,kerrizor/calagator,kerrizor/calagator,nblackburn87/calagator,reidab/calagator,CorainChicago/ActivateHub,cp/calagator-1,alexbeeken/calagator.org