Pouchdb: Checklist: deprecations for 6.0.0

[nolanlawson]

Following up from #5342, let's track what we need finished before we can publish 6.0.0:

• [x] remove new PouchDB().then() (https://github.com/pouchdb/pouchdb/pull/5319)
• [x] remove db.put(doc, id, rev) (https://github.com/pouchdb/pouchdb/pull/5311)
• [x] remove SQLite Plugin support, create separate plugin (#5519)
• [x] remove optionalDependencies (replaced with custom builds) (#5590)
• [x] remove extras (ditto)
• [ ] remove everything from dist except pouchdb.js, pouchdb.min.js, and pouchdb.next.js
• [ ] move other dist files to sub-packages, each sub-package has its own dist

Removing lie, defaults, and prefix seem controversial, so I propose we punt on those for now. For removing skipSetup/skip_setup and returnDocs/return_docs etc. I'd say the cost of maintaining backwards compat is lower than the cost of removing them, so I propose punting on that as well. Dropping bower/jsdelivr/cdnjs support also seems like more work than its worth right now. Ditto for removing pouchdb-http and db from the leveldb adapters.

I'd also like to consider publishing 6.0.0 as with a dist-tag of beta, which is a trick @boennemann explained to me that allows us to publish a "preview" version without making it the version that gets installed by default when you do npm install pouchdb.

[nolanlawson]

In case it's not clear, I intend to tackle all of those unchecked checkboxes, so unless someone else wants to take them up, I'm licking that cookie. :) The recent Lerna removals (#5550, #5583) were an effort on my part to simplify the build code in preparation for the deprecations.

[nolanlawson]

After talking with @gr2m and thinking about this a bit more, I think we should skip removing dist from the core package. A few reasons:

1. It's been too long since a release, let's get 6.0.0 out
2. Removing it would require tons of changes to our tests which largely depend on loading from dist
3. It's probably more complicated for users anyway. dist is designed for non-power users, and those users probably don't want to go hunting in sub-packages to find something.

So based on that, I'll cross out the last two items. I say once extras is out, we can release. I'll look into doing a npm prerelease (using dist-tags) this week or weekend. @daleharvey do you agree?

[garrensmith]

+1 from me

All misspelling thanks to my iPhone.

[gr2m]

The "remove extras" is ready via https://github.com/pouchdb/pouchdb/pull/5591 I think

[nolanlawson]

6.0.3 will be released today, which will be the "official" release. (6.0.0, 6.0.1 and 6.0.2 were tagged as beta.)