Update causes bookmarks and in-video clips to get deleted

[Segergren]

Bookmarks and clips in videos gets removed after a Plays update. This is probably because it's saved in LocalStorage.

[lulzsun]

The fix is done by importing and exporting the localstorage to a file in the cfg folder. This is done every time the webview is loaded.

This is a quick and lazy fix because we should be utilizing .metadata files that we are creating in the .thumbs folder instead of using localStorage. But this will do for now I think.