changed storage method names, added clear flag

[leastbad]

set_storage and remove_storage follow the naming convention used by every other operation.

I added a new optional clear flag to the remove_storage method that optionally clears all keys.

[marcoroth]

Wouldn't it make more sense to provide an extra clear_storage method that just clears the storage since it's also a method on it's own in the browser API?

[leastbad]

Maybe! I would defer to Nate's preference here - clearing is definitely a kind of removal.

Fwiw I'm definitely influenced by the reality that this seems like it'd be usually very rarely.

[hopsoft]

I like the semantic change here for consistency, but don't think we should drop the item suffix. I also like the idea of adding clearStorage. One other nitpick that I'd like to address while we're at it is to move

const storage = type === 'session' ? sessionStorage : localStorage

directly under the line where we destructure vars out of the config.

Update: leastbad#1

[leastbad]

Sounds good to me! I updated channels.rb with the new method names.