Update backbone-indexeddb.js
Update backbone-indexeddb.js

Backbone.sync now returns undefined (as it did before this pull request) if $.Deferred doesn't exist. This is, perhaps, a more graceful way of handling the dependency on $.Deferred.

Please let me know if you like me to handle the dependency differently.
zawaideh/indexeddb-backbonejs-adapter,zawaideh/indexeddb-backbonejs-adapter,superfeedr/indexeddb-backbonejs-adapter,superfeedr/indexeddb-backbonejs-adapter