See gh-5287

Remove accidentally committed SizeThreshold class.

* windows-build-fixes:
  Fix some Windows build issues

Closes gh-5640

* issue-5637-fix:
  Polish contribution
  Support max-http-header-size & max-http-post-size

Add `server.max-http-header-size` and `server.max-http-post-size`
properties and deprecate `server.tomcat.max-http-header-size`.

Fixes gh-5637
Closes gh-5641

* issue-5631-fix:
  Polish contribution
  Support ActiveMQ trusted packages

Ass support for white-listing specific packages or trusting all packages
when using ActiveMQ.

Fixes gh-5631
Closes gh-5644

Ensure any ChildManagementContext created to start a management server
on a different port uses the same EmbeddedServletContainerFactory type.

Fixes gh-5474

Update ServerProperties so that `null` values are not applied when
customizing the EmbeddedServletContainerFactory. Primarily changed to
stop `server.undertow.accesslog.enabled` from being blindly applied.

Fixes gh-5515

Update the auto-configured MessageChannelMetricWriter with
@ExportMetricWriter so that metrics are actually exported.

Fixes gh-5517

Update JettyEmbeddedServletContainerFactory so that requests other than
just GET, POST and HEAD are handled by the ErrorHandler.

Fixes gh-5367

Closes gh-2763

Add a note regarding the use of `@EnableCaching(proxyTargetClass=true)`
for beans that are not interface based.

Closes gh-5527

* image-banner:
  Add image banner documentation
  Rework ImageBanner Support
  Add ImageBanner color distance calculation
  Support image based banners

Closes gh-4647

Refactor several aspects of the ImageBanner:

- Extract a few new classes and methods from the previous code
- Directly encode ANSI rather than using `${}` properties
- Rework the scaling algorithm to prefer a fixed width
- Allow ImageBanner and TextBanner to be used together
- Rename several of the `banner.image` properties
- Add support for a left hand margin
- Add property meta-data

See gh-4647

Support CIE94 color distance calculations for improved ImageBanner
rendering. Based on code originally developed by Michael Simons and
added with his permission.

See gh-4647

Add ImageBanner class that generates color ASCII art based on an image
file (banner.gif, banner.jpg or banner.png).

See gh-4647

To overcome command length limits on Windows, IntelliJ IDEA may launch
an application with a single jar on the classpath that contains that
application's actual classpath in the Class-Path attribute of its
manifest. This would prevent DevTools restarts from working as it
only considered the single jar's URL when identifying changeable URLs
and ignored the URLs added to the classpath via the jar's manifest.

This commit updates ChangeableUrls when it is created from a
URLClassLoader to consider the Class-Path manifest attribute of any
jars in the class loader's URLs. This allows the full classpath to
be considered when identifying URLs that are changeable and that
need to be monitored for restart triggering.

Closes gh-5127

* gh-5617:
  Polish contribution
  Allow embedded Mongo's storage to be configured via the environment