Fixing tests.
Reverting those exit changes, seeking out bad at_exit gem code instead.
Setting a configuration option to allow at_exit hooks per discussion with @steveklabnik in #862
Updating changelog.
Merging in 1-x-stable.
Merge remote-tracking branch 'origin/feature/swap-reduction-862' into feature/swap-reduction-862
Merge pull request #878 from jonhyman/feature/swap-reduction-862

Feature/swap reduction 862