Update remotestorage.js to 0.10.0 beta

This updates remoteStorage to the latest version.

The release includes a lot of improvements and bugfixes. Especially the anonymous mode and problems when using a storage account with the latest spec are fixed now. See the [changelog](https://github.com/remotestorage/remotestorage.js/blob/master/CHANGELOG.md) for details.

It would be really great if you could have a look at this soon.

I also deployed this version of Litewrite at https://litewrite-rs010.5apps.com, so you can try it out more conveniently ;)