Fixes gh-1328

Fixes gh-1321

Previously, the ErrorPageFilter would always flush the response
buffer, irrespective of the request being asynchronous. This could
lead to a response being committed prematurely, preventing, for
example, headers being set by subsequent processing.

This commit updates ErrorPageFilter so that in the success case
(status < 400) the response buffer is only flushed if the request is
not async (determined by calling request.isAsyncStarted()). If an
exception's been thrown or the status is >= 400 the response buffer
is always flushed.

Fixes #1316

Previously, Repackager would repackage a jar file as many times as
it was asked to do so. This lead to problems if a user made a mistake
when using Maven that led to the package phase being driven twice,
for example by running "mvn clean install package".

This commit updates Repackager so that a repackage call becomes a
no-op if the source jar's manifest already contains the
Spring-Boot-Version attribute which is added by repackaging.

Fixes #1251

Update EnvironmentEndpoint and ConfigurationPropertiesReportEndpoint
to allow regex patterns in `keys-to-sanitize`.

Fixes gh-1245

Use Java 7 `registerAsParallelCapable` and `getClassLoadingLock` methods
when possible. This should improve performance when running on JDK 7+
whilst still remaining JDK 6 compatible.

Closes gh-1284

Rework flexible PublicMetrics registration introduced in 2be6b3e4 to
restore compatibility with v1.1 VanillaPublicMetrics. The new
MetricReaderPublicMetrics class now exposes metrics from a MetricReader
and VanillaPublicMetrics is deprecated. The MetricsEndpoint can now
exposes a collection of PublicMetric interface directly.

See gh-1094

Rename the newly introduced @ConditionalOnProperty `match` and
`defaultMatch` attributes to `havingValue` and `matchIfMissing`.

Also added a new `name` attribute as an alternative to `value` to
aid readability.

Closes gh-1000

The presense of store-specific RepositoryConfigurationExtension beans
is used to disable auto-configuration for JPA, Mongo, and Solr

Closes #1267

Closes #1307

Closes #1305

Previously, when running on Java 7+, the JDBC query driven by
DataSourceHealthIndicator resulted in a call to
ResultSet.getObject(index, Object.class). When using MySQL's JDBC
driver this failed with an SQLException with the message "Conversion
not supported for type java.lang.Object". The problem does not occur
on Java 6 as the overload of getObject that takes a type does not
exist; ResultSet.getObject(index) is called instead and MySQL happily
returns whatever type it deems to be appropriate for the column.

This commit updates DataSourceHealthIndicator so that
ResultSet.getObject(index) will always be used, irrespective of the
version of Java that Boot is running on.

Closes #1306

Closes #1304

Closes #1120

The original fix for gh-1293 (commit 05e6af23) caused test failures due
to the fact that Spring Boot's MappingJackson2HttpMessageConverter was
added before Spring's default StringHttpMessageConverter.

This commit changes the HttpMessageConverters logic so that additional
converts are added just before any default converter of the same type.
This allows additional converters to be added whilst still retaining
the sensible ordering of the default converters.

Fixes gh-1293

It was incorrect to simply replace existing instances because you can't
tell from the instance which media types and java types it supports. This
fix just prepends the custom converters so they get higher priority.

Fixes gh-1293

Since Spring 4.0.4, it's now possible to use both classes and
locations to provide a test's configuration.

Closes #1300

Closes #1299

Previously the server was started to make the ServletContext
available, then, to prevent requests from being handled before the
application context had been started, the connectors were stopped.
Once application context startup had completed, the connectors were
then started again. In addition to being somewhat inefficient, this
caused problems on FreeBSD where stopping the connector didn't free
up the port quickly enough for the subsequent start to then be able
to bind to it.

This commit updates the Jetty startup logic to be closer to the logic
that's used for Tomcat. Before the server is started, the configured
connectors are cached and then removed. The server is then started
without any connectors. Once application context startup has
completed, the connectors are reinstated and started.

Fixes #968