Tiled Gallery: No more carousel when it is off.

Carousel is no longer shown for Tiled Galleries when clicking a gallery item, when it is turned off in the Jetpack settings.
Tiled Gallery: Always open carousel in widgets.

When the user has specified that the widget gallery should link to carousel, we ignore Jetpack settings and let it use Carousel anyway.
Merge pull request #517 from rase-/fix/carousel

Tiled Gallery: Don't trigger Carousel from a Tiled Gallery when the Carousel module is explicitly disabled.

Does not prevent users from choosing the Carousel option in the Gallery widget even though Carousel is disabled.