RFC: Micro-tipping Feature

I just learned from [a thread on twitter](https://twitter.com/taoeffect/status/774840387156398080) about a [Microtip Meta Tag Specification](https://autotip.io/docs/microtip-meta-tag).

This spec invites devs to add a tag to their websites like this:

``` html

```

The idea is that any page you visit that adheres to this standard would be automatically tipped a set amount you specify on your visit.

Looks like [Brave wants to adopt it this week](https://twitter.com/BrendanEich/status/774833769056309248), too!

A couple different ways we could go about it:
- You only auto-tip when unlocked
- You fund a special auto-tip account that stays unlocked.

Some UX options:
- Leave it on all the time by default (clearly wrong to me).
- Leave it hidden in settings. (a bit cowardly for a feature we choose to implement)
- On setup, or for users who have never specified, we show a splash screen "would you like to auto-tip web sites?", allows setting currency value. (like 5 cents)
- Has the benefit that it provides the user an explicit screen to set desired currency, without ever deliberately visiting the settings.

As the microtip standard supports specifying a division of the tip, I'd be curious of nice single-tx ways we could achieve this. Could we make an auto-tip contract, that allows submitting an array of account-ratio tuples?

Start by reading the linked Microtip Meta Tag Specification and the issue's proposed UX options. No files, tests, entry points, or acceptance criteria are identified, so a contributor would first need to define the integration and user-flow scope before implementation or validation is possible.

Written by the indexing model from the issue text.