Add ModalOverlay
Add dismissOnExternalInteraction property

Conflicts:
	test/ui/overlay-spec.js
	ui/overlay.reel/overlay.js
Add Overlay and ModalOverlay blueprints
Extend component mock and add rootComponent mock
Extend dom mock

Add HTML dom node and createElement function.

Conflicts:
	test/mocks/dom.js
Add hasModalMask property to ModalOverlay
Disable closing on external interaction on ModalOverlay
Add AbstractAlert
Add Confirm

Conflicts:
	test/run.js
Add AbstractAlert and AbstractConfirm blueprint
Fix abstract alert and confirm tests
Add OKButton and CancelButton constants
Fix failing specs in overlays.
Merge pull request #1299 from asolove/overlays

Overlays