Issue: SPR-17450

Refactor AbstractEncoderTestCase to resemble AbstractDecoderTestCase

Issue: SPR-17449

Introduce new base test case for decoder tests, and use it.

Issue: SPR-17449

Jim Showalter found two typoes in the web section. This PR fixes them. Thanks, Jim.

Issue: SPR-17459

Issue: SPR-17459

Issue: SPR-17388

Issue: SPR-17489

Issue: SRP-17475

Update the ServerHttpRespnose contract to indicate that server specific
sub-classes should fall back on the default status, if a status code
has not been set explicitly.

Issue: SPR-17368

This commit reverts the first optimizations listed in
fa096dc6, as the default delimiters
do vary, namely by the charset given in the message mime type.
The mimetype charset might not be compatible with ASCII (i.e. anything
but UTF-8 or ISO-8859-1, for instance it might be UTF-16), and will not
successfully find the default delimiters as a consequence.

Added test to indicate the bug.

Introduce new base test case for encoder tests, and use it.

Issue: SPR-17449

Introduce a data buffer factory that can check for memory leaks in
@after methods.

Issue: SPR-17449

Issue: SPR-17086

Issue: SPR-17460

Issue: SPR-17486

Issue: SPR-17486

This commit was inspired by the following question on Stack Overflow.

https://stackoverflow.com/questions/53236807/spring-boot-testing-run-script-in-a-nested-test-sql-script-sql

Issue: SPR-17482

Issue: SPR-17465

Issue: SPR-17473

Issue: SPR-17267
Issue: SPR-17372

Issue: SPR-17476

* pr/2011:
  Fix typo

Closes gh-2011

Issue: SPR-17458

Issue: SPR-17464

Issue: SPR-17445

Issue: SPR-17442