Bugfixes and tweaks.

* Fixed a bug with dynamically defining getters and setters for classes breaking platform updating.
* Fixed a visual bug causing the experimental tag to be hidden when experimental features are shown, and the tag to be shown when featurea are hidden.
* Tweaked positioning of the 'EXPERIMENTAL' tag on the popup so it's not overlapping the platform tag.
* WIC is now persistent.
* Removed the update URL in preparation for uploading to the Chrome store.