Make Extension Configurable

[davidblitz]

I like the idea of this extension! I would like to be able to set a default expiration date and automatically bookmark/save expired tabs

[jmswisher]

Ditto on setting a default expiration date. Right now, all my tabs default to expiring in 2099. Who wants to go in and change the expiration on almost every tab? I'd rather have a short default, and manually set it longer for just a few of them.