ADD option to discard pages with different timeout on a separate list

[allanlaal]

Use case 1:

dirty fix for #108

Use case 2:

there are sites, where I want tabs to be eventually discarded, but not as fast as the default

[allanlaal]

maybe overkill, but having 1..N of these different-timeout-lists would be very handy and wouldn't prolly cause much extra load either :)