[front-end] don't check that page subscriptions are undefined
[front-end] ui-routers pageConfig resolve doesn't depend on EventEmitter
[front-end] event subscriptions are updated when widget's instanceName is changed
[front-end] APIUser and EventPublisher constructor can work with undefined instanceName
[front-end] update to angular-json-editor@0.1.6; remove WidgetModalConfigButtonsController
[gulp] reorder gulp tasks

The following order should be used:

default
build
build-subtasks
test tasks
watch tasks
[gulp] handle errors in new tasks gracefully (such that gulp watch doesn't crash)