* pr/8683:
  Polish "Add support for HotSwapAgent to devtools"
  Add support for HotSwapAgent to devtools

Closes gh-8683

HotSwapAgent is an open source competition to JRebel. This commit adds
"org.hotswap.agent.HotswapAgent" to the list of known Java agent based
class reloaders. This causes same behavior as when JRebel is used: a full
restart is NOT triggered when any class changes, however LiveReload event
is still triggered.

See gh-8683

* pr/8703:
  Polish "Document HTTP response format of health endpoint"
  Document HTTP response format of health endpoint

Closes gh-8703

Add HTTP response format details for health endpoint, including default
status codes and sample responses.

See gh-8703

This commit changes the solr health indicator to request the status of
all available cores, rather than invoking a generic ping on the admin
handler.

Recent versions of Solr now have a ping handler per core and the general
admin handler is gone, leading to incorrect health status. For backward
compatible reason the `solrStatus` attribute is kept to `OK` if all cores
are running properly (that's actually `0` behind the scenes).

Closes gh-8463

Closes gh-8876

* pr/8829:
  Allow to disable max http post size limit

Closes gh-8508

* pr/8866:
  Upgrade to Spring Kafka 1.1.4

Closes gh-8866

It should have been removed in 2522a5f9

Closes gh-8702

Closes gh-8847

Closes gh-8846

Closes gh-8845

Closes gh-8844

The neo4j embedded driver no longer embeds the neo4j kernel and users are
expected to add that dependency manually. We don't provide dependency
management for any of them so this commit updates the documentation to
refers to the official documentation.

Closes gh-8567

Closes gh-8841

Closes gh-8840

Closes gh-8839

Closes gh-8838

Closes gh-8837

Closes gh-8836

Closes gh-8835

Closes gh-8834

Remove call to `.close()` which was accidentally left in after some
performance testing.