Refactoring — multiline error handling.

See http://stackoverflow.com/a/27038608/186202

Use: grin 'if \(err\)' loop/ test --emacs | egrep -v 'throw' | egrep -v 'return'
To verify.
Merge pull request #263 from mozilla-services/refactoring-error-handling

Refactoring — multiline error handling.