OZP-296: Make sure all testacular tests produce code coverage

- set window.onerror to empty function to fix so that mocha doesn't
fail tests
Merge branch 'feature/ozp-64-preferences-api'

Merge of changes in Preferences branch so far
OZP-64 Added logic for populating the list of required widget ids for the widget definitions
OZP-499 Switch from Sprint 4 to Sprint 5.