New actions to receive changes

[jgillich]

http://docs.couchdb.org/en/stable/api/database/changes.html

There are multiple ways to receive changes:

• Polling (without feed query): Send a request, get a response. Easy.
• Long Polling (feed=longpoll): Send a request, get a response when a change happens. Primarily for browsers, IMO this isn't needed, or at least not very high priority.
• Continuous (feed=continuous): Send a request, keep the connection open and continuously get changes. I want this.

[cmbrandenburg]

The couchdb crate has this—see here and here. I'll port it over.

[jgillich]

Hah, awesome. 👍