fix(runner): prevent source-map-support module from exiting process on `uncaughtException` exception

See #876 (https://github.com/angular/protractor/issues/876) for more info about the reason for this change
fix(runner): summarise comments as advised by @juliemr
Merge remote-tracking branch 'origin/fix/cucumberjs-stop-on-step-failure-based-on-1.3.1'