Closes gh-16428

Closes gh-16422

Closes gh-16028

Closes gh-16356

Closes gh-16349

Closes gh-16424

Closes gh-16348

Closes gh-16352

See gh-16421

Closes gh-16421

See gh-16418

See gh-16418

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

Closes gh-16068

Closes gh-16346

Closes gh-16345

Closes gh-16359

Closes gh-16358

See gh-16400

Closes gh-16400

Closes gh-16339

Closes gh-16338

In addition to upgrading to Jetty 9.4.15, this commit updates the
KeyStores used in embedded container testing to add to their entries
subject alternative name extensions for localhost and 127.0.0.1. As
of 9.4.16, Jetty requires the SAN extensions.

Closes gh-16188

Closes gh-16372