Don't encode the scope parameter.

When passing in 'openid profile' as the scope parameter, the jQuery call results in a double encoding, which means that the server does not understand the scope parameter and does not return an id token.
Encode the options.scope parameter when concatenating strings.
Don't clear the entire local storage when logging out.

Applications use local storage for many things. Only clear out the storage keys that are being set by this plugin.
Merge pull request #3 from TeamPraxis/master

Don't encode the scope parameter.