Issue: SPR-16479

Issue: SPR-16372

Issue: SPR-16456

Issue: SPR-16478

* pr/1569:
  Fix typo

Closes gh-1569

* pr/1671:
  Change this "try" to a try-with-resources

Closes gh-1671

* pr/1670:
  Collection.isEmpty() should be used to test for emptiness

Closes gh-1670

* pr/1669:
  Polish

Closes gh-1669

This commit introduces DataBuffer.asInputStream(boolean), that can
release the underlying buffer when the stream is closed.

Furthermore, this commit adds additional javadoc.

Issue: SPR-16444

Issue: SPR-16465

Issue: SPR-16472

The very short, summary mini-sections confuse the client-side code that
highlights the TOC item. This commit removes the sub-sections.

After this commit the use of interval in tests is combined with
take(n).onBackpressureBuffer(n) to ensure emissions don't fail if the
fixed rate is exceeded (e.g. on slow CI server).

Tests that verify N number of items followed by verifyOnComplete()
should set the number of emissions to N.

Tests that verify N number of items followed by thenCancel() should
set the number of buffered to an arbitrary number greater than N.

Issue: SPR-16463

Issue: SPR-16461

Issue: SPR-16151

This commit updates HttpWebHandlerAdapter and
ResponseStatusExceptionHandler in order to specify the method/uri in the
logged message.

It also logs a WARN message for bad request (400) HTTP responses in
order to get some logs when an exception is thrown due to client error
(unable to deserialize request body for example).

Issue: SPR-16447

* pr/1606:
  Replace manual array copy with native method call

Closes gh-1606

Previously MockHttpServletRequestBuilder calculated the pathInfo from the
provided URL without decoding the value. This meant that the pathInfo
incorrectly included URL encoded values.

Now MockHttpServletRequestBuilder properly decodes the pathInfo.

Fixes: SPR-16453

Issue: SPR-16337

Issue: SPR-16458

Issue: SPR-16457