Closes gh-16333

See gh-16418

Closes gh-16351

Closes gh-16354

Closes gh-16353

Closes gh-16418

Remove a few items that are no longer necessary.

Update the eclipse setup files and contributing instructions for
compatibility with the latest Eclipse 2019-03 release. This commit
reverts the use the HTTPS in the `.setup` file namespace (since it
breaks the setup editor). The `xsi:schemaLocation` section still
uses HTTPS for actual XSD resolution.

See gh-16245

See gh-16068

* gh-16087:
  Polish "Ensure that MongoClient's EventLoopGroup is shut down during context close"
  Ensure that MongoClient's EventLoopGroup is shut down during context close

Closes gh-16087

See gh-16087

See gh-16087

Closes gh-16189

Closes gh-16040

Closes gh-16068

Closes gh-16347

Closes gh-16346

Closes gh-16345

Closes gh-16360

Closes gh-16359

Closes gh-16358

Fixes gh-16177

Closes gh-16404

See gh-16400

Closes gh-16400