Fixing jQuery.uuid

Since jQuery.uuid does not exist anymore I changed it to Ember.uuid
https://github.com/emberjs/ember.js/pull/1481
Fixes an issue where the style was written to the HTML-tag instead into the style attribute

The style is first shown, when the observer fires for the first time.

Also with background:#fff bound, it writes background:#FFF direktly
into the HTML-Tag and the style-attribute was empty
Merge pull request #8 from Handfeger/master

jQuery.uuid has been removed