Implement local storage infrastructure

[brson]

Servo doesn't have any local storage. This will be needed for history, bookmarks, caching and a million other things. At this time we are inclined to use LevelDB for everything, so a good place to start would be LevelDB bindings. Then move on to some of the common browser features and figure out how to integrate them into the engine.

[amuxtux]

Should we consider security features at the moment (e.g. secure storage)

[brson]

In my opinion we should design with security and privacy in mind, but we don't necessarily need to implement security features yet.

[brson]

I just noticed some LevelDB bindings here. Might be a good starting point.

[Manishearth]

triage: We have session storage, and a session storage object that pretends to be local storage

[jdm]

The features described here aren't related to sessionStorage. I don't see a reason to keep this open right now. We should discuss persistent storage requirements as needed.