Closes gh-4019

Closes gh-4124

See gh-4019

Closes gh-3576

Previously, EndpointWebMvcChildContextConfiguration would attempt to
create a /error endpoint, irrespective of whether or not the parent
had such an endpoint. If the endpoint was disabled in the parent this
would cause a failure due to the absence of an ErrorAttributes bean.

This commit updates EndpointWebMvcChildContextConfiguration to make
the creation of its /error endpoint conditional on the existence of
an ErrorAttributes bean.

Closes gh-4164

Closes gh-4151

Closes gh-4150

Closes gh-4149

Closes gh-4148

Prior to 8.0.28 Tomcat required the key store and trust store (if any)
to be available directly on the filesystem, i.e. classpath: resources
would not work. Tomcat 8.0.28 removed this limitation.

This commit updates to Tomcat 8.0.28, updates the tests to verify
the new Tomcat capability and removes the obsolete documentation of
the restriction.

Closes gh-4048

Previously, the parent context was only considered when the builder
was used to run the application. If the application was built using
the builder and then run using SpringApplication.run, the parent
context was not considered.

This commit updates the builder to consider the parent both when it's
used to run the application and when it's used to build the
application that will later be run via SpringApplication.run

Closes gh-4014

Gradle 2.0, and only 2.0, requires a Plugin implementation to be
public. The changes made in gh-4113 (9c14ed35) made the class
package-private.

Closes gh-4139

Closes gh-4113

Closes gh-4145

Update Eclipse settings to make use of a custom Spring formatter
implementation. Using a custom formatter allows us to fix a couple of
issues with the version that shipped with Eclipse Mars.1 (Eclipse bugs

The custom formatter also means that it is possible to use Groovy
Eclipse despite the fact that it has formatter regressions (see
https://github.com/groovy/groovy-eclipse/issues/142).

Fixes gh-4136

Closes gh-4124

Previously, JarFileArchive would always unpack any entries marked for
unpacking to ${java.io.tmpdir}/spring-boot-libs. This could cause
problems if multiple Spring Boot applications were running on the same
host:

- If the apps are run as different users the first application would
  create the spring-boot-libs directory and the second and subsequent
  applications may not have write permissions to that directory
- Multiple apps may overwrite each others unpacked libs. At best this
  will mean one copy of a jar is overwritten with another identical
  copy. At worst the jars may have different contents so that some of
  the contents of the original jar disappear unexpectedly.

This commit updates JarFileArchive to use an application-specific
location when unpacking libs. A directory beneath ${java.io.tmpdir} is
still used but it's now named <jar-file-name>-spring-boot-libs-<uuid>.
A loop, limited to 1000 attempts, is used to avoid problems caused by
the uuid clashing.

Closes gh-4124

Commit 09395f95 updated the samples to require Java 8. This commit
updates the Travis configuration to build with Java 8.

Closes gh-4133

Prior to this commit, EmbeddedWebApplicationContext would perform its
close processing and then stop the embedded container. This could
lead to the closed context's dispatcher servlet handling an HTTP
request and refreshing the context again. This opened up two
possibilities that we need to avoid:

1. Another HTTP request could be received by the dispatcher servlet
   while the context is still being refreshed. This could lead to the
   context being used before its refreshed. I believe this could be
   the cause of the current modification exception described in
   gh-3239 and SPR-13123.
2. It can lead to a race during shutdown as the shutdown hook's
   attempt to close the context races with the refresh initiated by
   the HTTP request. This is possible as the shutdown hook bypasses
   the sychronization on startupShutdownMonitor that would normally
   prevent refresh and close from occurring in parallel. This race
   can lead to a deadlock as described in gh-4130

Closes gh-4130

Fixes gh-4111

Replace existing Groovy code with Java since the Groovy Eclipse tooling
currently forces the use of an old jdt plugin which has formatter bugs.

Fixes gh-4113

Update the samples and integration tests to use Java 8. There's no
specific reason to keep them on Java 6 and it helps keep Eclipse happy
if we upgrade.

Ignore the `helpmojo` goal to save needing an additional Eclipse plugin.

Mirrors of archive.apache.org only mirror the latest release of each
project so, as new releases are made, builds using older versions will
break as the mirrors are updated.

This commit updates the Tomcat deployment test to use the main Apache
archive site. This should provide long-term access to Tomcat binaries,
improving build stability and ensuring that tagged builds are
repeatable.

Backport of 5f087e64

Closes gh-4095

See gh-4098

See gh-4098

Previously, MetricsFilter would treat async requests the same as
sync requests and would record their response status as soon as the
request had been processed by the filter chain. This would result in a
200 response being recorded and the actual response status produced by
the async processing being ignored. Furthermore, the time that was
recorded for the request would not include the time take for any async processing.

This commit updates MetricsFilter to check whether or not an async
request has been started before it records the metrics for the request.
In the event of an async request having been started no metrics are
recorded. Instead, the StopWatch is stored in a request attribute that
is then retrieved during the filtering of the request’s async
dispatch(es). Once the async processing has completed (isAsyncStarted()
returns false), the StopWatch is stopped, removed from the request’s
attributes and the metrics for the request are recorded.

Closes gh-4098

Closes gh-4089

Update all TemplateAvailabilityProvider implementations to use the
relaxed property binder. Also fix FreeMarkerTemplateAvailabilityProvider
to use `template-loader-path` rather than `path`.

Fixes gh-4085

Previously `spring.velocity.charset` only controlled the output encoding
with the templates being loaded with the default encoding. We now
consistently set the same value for both the input and output encodings.

It is still possible to override it to a different value using
`spring.velocity.properties.input.encoding`

Closes gh-3994

Update RelaxedDataBinder so that both `.` and `_` are considered in
getPropertyValuesForNamePrefix(...).

With Spring Boot 1.2.5 binding environment variables of the form
`FOO_BAR_BAZ` to `@ConfigurationProperties(prefix="foo-bar")` objects
worked thanks to a happy accident. When `PropertySourcesPropertyValues`
processed a non enumerable `PropertySource` it called the resolver
with a property name `FOO_BAR.BAZ`. A `SystemEnvironmentPropertySource`
will replace `.` with `_` and hence find a value.

Commit 1abd0879 updated non enumerable processing such that the resolver
was never called.

Replicating the problem is quite involved as you need to ensure that you
have both a SystemEnvironmentPropertySource and a non-enumerable
property source (e.g. RandomPropertySource). A test has been added to
PropertiesConfigurationFactoryTests which passes on 1.2.5, fails on
1.2.6 and passes again following this commit.

Fixes gh-4045

Closes gh-3913