EDITING: Fix Saving Multiple Times

Also fixes various other issues.

Moving everything under a meta property or even attributes._meta proved to be more problematic than expected, for various reasons, including keeping the nice backbone-associations chaining when overriding get, and especially set.

Instead, this solves the issue by overriding `save()` to directly use `sync()`.  Some Backbone functionality is currently lost that we're not using anyway (like `save(properties)`), so this should probably be changed in the future with a more comprehensive solution.

These fixes also made some of the changes in the editable.coffee aloha code no longer necessary, so that code was simplified as well.