Finish refactoring how we map filters to actions

[dtauerbach]

Right now the actual blocking and subscription lists have been refactored, but not the popup.js logic. We need to think carefully about how to refactor.

1. Should there be an Action object, or is it OK to just have an enum and represent actions by string (e.g. "cookieblock")?
2. We should change getBlockedData in background.js to return to actions themselves to popup.js, not the list of subscriptions which fired/didn't fire.
3. We need to somehow be able to determine if a user changed a setting. Right now if I load something in Tab1, then browse to Tab2, it's possible that something will have been added to the frequencyHeuristic subscription from Tab1 that was previously unblocked. Then if I go back to Tab1, we need to update, else it could look like the user changed.

[dtauerbach]

Working in fix-lists branch.

For 1, represented as a sort of subscription list "lastaction" in the dict that tracks what we are blocking by tab; this is done. 2 is done.

For 3, the idea is for user-set actions for domains to have a css class, so we can, for example, display a little lock or something indicating the user has locked this setting. User settings will always override extension permanently, so if a use changes a setting for a domain to being blocked, it will stay that way until the user changes it back. A future todo is to allow the user to return responsibility to the extension somehow for a particular domain.

[dtauerbach]

Done with merging "fix-lists" branch.