Use "return" instead of "exit" where possible, especially in
function definitions.

Also fixed the exit codes to match the LSB spec for some specific
conditions (fixes gh-3521).

Fixes gh-3199, fixes gh-3535

Users sometimes create beans of type Converter and don't expect that to
automatically trigger a cascade of early initialization. This change adds
a qualifier to the Converters that are used by @ConfigurationProperties,
so they can be isolated (and simple).

Fixes gh-2669

Spring MVC requires all handlers for the same path to be on the same handler
so if anyone wants to add new handlers for different content types they
have to copy a lot of code from BasicErrorController. This change increases
the visibility of the basic utility methods in BasicErrorController so that
custom handlers can be added easily.

Fixes gh-3828

1.3.0.M4 tightened up the configuration property binding such that
ignoreUnknownFields = false now works as intended. Unfortunately, this
has led to some complaints as applications that worked with 1.2.x have
stopped working. For example, a SERVER_HOME environment variable does
not cause a failure in 1.2.x despite there being no home property on
ServerProperties but will now fail in 1.3.0.M4.

This commit updates RelaxedDataBinder to ignore binding failures for
properties that come from a source outside of the application’s control,
namely environment variables and system properties.

Closes gh-3775

Remove stale test class

This commit adds a new annotation, @ServletComponentScan, that can be
used to enable scanning for @WebFilter, @WebListener, and @WebServlet
annotated classes. Registration beans will be automatically created for
any classes that are found, with the configuration derived from the
annotation.

Closes gh-3406
Closes gh-3526

Closes gh-3827

* pr/3821:
  Fix typo

Closes gh-3821

Closes gh-3823

Previously, native cache libraries were favored over a standard JSR-107
implementation. If a user has a working setup using JCache with one
provider and switch to another provider, his setup may be broken if we
happen to provide a native support for the new provider.

We now consistently favor JSR-107 if it is present. Native support can
still be enabled via the `spring.cache.type` property.

Closes gh-3822

* pr/3794:
  Disable resource cache when DevTools is enabled

Closes gh-3794
Closes gh-3739

* pr/3810:
  Fix typo

Closes gh-3810

* pr/3809:
  Fix typos

Closes gh-3809

* pr/3807:
  Polish
  Fix springloaded version

Closes gh-3800

Closes gh-3807

Conflicts: MessageSourceAutoConfiguration.java

Fixes gh-3803

Fixes gh-3782

Previously we had to create a fake Properties object as the factory did
not provide individual setters for the SSL configuration. This has been
added as part of Spring AMQP 1.5.0.RC1 so we're using those instead.

Closes gh-3754

Checking for a prefix "counter." is more correct than "counter" because
the readers (repositories) assume the former prefix is there.

Fixes gh-3801

Closes gh-2899

This commit enhances RelaxedDataBinder to include information about the
origin of a property (its original name before any prefix was removed
and its source) when it encounters an unwritable property. For example,
launching an application with a SERVER_HOME environment variable
configured will produce the following failure message:

Failed to bind 'SERVER_HOME' from 'systemEnvironment' to 'HOME' property
on 'org.springframework.boot.autoconfigure.web.ServerProperties'

Closes gh-3778

Closes gh-3781

Previously, manual meta-data were added to the existing set of entries
which could lead to duplicates if a manual entry is meant to complement
a property that is detected via the processor.

We now match the name and type of the item against the auto-detected
entries. If no match is found, we add the extra entry as we did before.
If a match is found we override the description, default value and
deprecation information.

Closes gh-3562

See gh-3792

Closes gh-3792

* pr/3793:
  Fix link to exec maven plugin

Closes gh-3793

Closes gh-3787