Advanced tweet actions

[keithamoss]

c.f. #30

Tasks will be displayed as native content (tweets, grams) with relevant actions: reply, quote + retweet. Once an action is taken the user should be prompted to "mark as done".

Replying will happen in-line if we're under the rate limit for this 15 minute block. If not, and the backend returns a rate limit error, we'll fallback to modals using web intents.

If we can, let's cache our replies in the database to avoid extra API calls to show.status. (c.f. #15)