Use preventDefault when dropping

[jrjohnson]

Without this Firefox sometimes follows a link to a random numeric place.

This appears to be a recurrence of #10. It can be seen on the dummy app most repeatably by

1. navigating to the Simple Sorting with Ember Data example
2. Click and drag from the text of the third item
3. Drop it so the text you're dragging falls in the space between the first and second item.

Adding a preventDefault call to the event solves this issue and prevents firefox from attempting to open a random URL like http://702700786646/. I don't think it's possible to add tests to this.

[jrjohnson]

@dgavey / @mharris717 I hope you don't mind a bump on this. It's causing errors for our users and I'd prefer not to recommend they use chrome.

Thanks! (and thanks for the addon, saved us a mullion hours of work!!!)

[dgavey]

I'll try and get a release out tonight. There should be no reason to rely on my release for your users though. You could always change the package.json to point to your account and branch with the fix in the mean time.

[jrjohnson]

Thanks @dgavey, I'm ok with that solution though I prefer to not depend on my branch, but on the commit here since then I know it's actually in and just waiting on a release. When I depend on my branches I can't really write off the bug as fixed upstream. This is my problem though, not yours and you are right I don't need to rush you at all.