Closes gh-5801

Closes gh-5716

It is legal for an annotation to be annotated with itself. Previously,
when searching for meta annotations this could lead to a stack overflow.
This was likely to occur when using Kotlin as, like Java, its Target
annotation is annotated with itself. A stack overflow doesn’t occur
with Java’s Target annotation due to some short-circuiting logic for
annotations in java.lang.

This commit updates the logic for finding meta-annotations to
short-circuit when an annotation that has already been seen is
encountered.

Closes gh-5902

Closes gh-2481

Closes gh-5898

Closes gh-5277

See gh-5901

While working on gh-5309, a regression was introduced and fixed right the
way on master. Unfortunately, the fix wasn't applied to `1.3.x` as it
should have been.

This commit applies 6dd84159 to `1.3.x`

Closes gh-5901

Closes gh-5896

The intention in 1.4 is for the deprecated testing functionality to
behave exactly as it did in 1.3. To help with this, this commit
updates SpringApplicationConfiguration to use
SpringApplicationContextLoader as its loader, just as it did in 1.3.

Closes gh-5882

- Use the latest Docker image for Ubuntu 14.04 LTS based tests
- Add Ubuntu 16.04 LTS based tests

Closes gh-5868

Closes gh-5864

Previously, Spring Session would be auto-configured by the mere presence
of Spring Session in the classpath. This was fragile as determining a
store type according to the environment could easily change when the
classpath of the project changes.

This commit makes the store-type property mandatory. If it is not set,
Spring Session is no longer auto-configured.

Closes gh-5838

* pr/5886:
  Upgrade to Spring AMQP 1.6.0.RC1

Closes gh-5886

* pr/5887:
  Upgrade to Spring AMQP 1.5.6

Closes gh-5887

Closes gh-5885

Closes gh-5881

The TestRestTemplate is deprecated (so people can still use it)
but unusable because it only has constructors which depend on the
new options enum.

Anyone who is extending InfoEndpoint (per the docs) in 1.3 can
continue to compile their code until they have time to adapt
to the new model.

Closes gh-5322

This reverts commit d6a424f9.

Closes gh-5361

# Conflicts:
#	spring-boot/src/test/resources/org/springframework/boot/env/test-encoded.properties