Prevent EmptyStackException in case no stack of prompts is empty
Add some tests for profile behaviour

Ordering: profiles are applied in order (from the active profiles
list in the Environment), with the last one winning as far as
property values goes. This *does* mean that a profile activated
inside application.yml is applied last and hence takes precedence.
It's debatable whether that is the right semantics, but that's
what it is for now.

Re gh-342: a profile added via SpringApplication also takes
precedence over one added on the command line. Also debatable
but at least it's predictable.

Naming: a profile adds "#<profile>" to the end of a property source
name (no more, no less)
Dependency version upgrades

 - spring-integration-core 3.0.1.RELEASE (closes #360)
 - Logback 1.1.1 (closes #361)
 - maven-settings-builder 3.1.1 (closes #359)
 - maven-aether-provider 3.1.1 (closes #356)
 - jopt-simple 4.6 (closes #357)
 - SLF4J 1.7.6 (closes #318)
Add test case for profile ordering

The command line profile (or equivalently System property) is
not winning right now. Arguably that should be fixed. (Thinking...)

Relevant to gh-342
Straighten out profile ordering semantics

Here's what I think works best:

* Any profile in the Environment before application.yml
is processed takes precedence (i.e. it will be last in the
list of active profiles in the live app)

* Any profile in the Environment before SpringApplication
starts takes precedence (so any added on the command line or
with System properties come after ones added using
the SpringApplication API)

* The order of profiles in application.yml is irrelevant -
profiles are applied in the order they come out of
Environment.getActiveProfiles()

Fixes gh-342
Be defensive about Spring Security dependencies

In particular don't assume that Spring Security Web is on the
classpath, just because Spring Security Core is.

Fixes gh-363
Add support for Spring Loaded in Maven and Gradle

Requires Loaded 1.1.5 (or better).

For Maven you can just add springloaded to the dependencies of the
spring-boot plugin (and also set MAVEN_OPTS=-noverify).

For Gradle add springloaded to the build dependencies (-noverify
can be added by the plugin).

In both cases there is also support for adding an arbitrary java agent
via configuration. Samples are provided in
spring-boot-sample-[simple,web-ui].

The ApplicationPlugin is only added if there is no JavaExec task
already present, and additionally it computes its own man class if
none is provided. So "gradle run" and "gradle bootRun" look
superficially similar, but "bootRun" has extra options, including
the agent and Loaded support.

Fixes gh-251, gh-183
Add snakeyaml to spring-boot-starter

Fixes gh-366
Update YAML refs in docs
Investigated JSP support

Summary: Tomcat works with WARs. Jetty doesn't work.

See gh-367
Revert change that breaks tests in werid way
Add JettyServerCustomizer for Jetty container customization

E.g. can be used to add SSL support to a Jetty container, similarly
to a TomcatConnectorCustomizer.

Fixes gh-345
Polish
Restore loading order of 'application.properties'

Restore the order that `ConfigFileApplicationListener` attempts to load
application.properties so that local files always have a higher
precedence than bundled classpath files.

This fixes a regression introduced with 1.0.0.RC2.

Fixes gh-370
Ensure DispatcherServlet is available in a deployed WAR

The DispatcherServletAutoConfiguration had a condition on it that
meant it wasn't used at all if there was no EmbeddedServletContainerFactory.
It's amazing that any WAR ever deployed.

Also added some info logging to servlet and filter registrations.
Try to make Jetty scan TLDs in nested JARs

Jetty apparently does it differently (different version of
Jasper maybe), so you need a unique jarFileURL for each
nested JAR (previously they were all set to the parent
archive URL).

Also added the root of the main archive as a valid
document root.

For gh-367
Omit jar: prefix from jarFileUrl
For pre-initialization phase use console only

Added basic-* log configuration files that are loaded in the
beforeInitialization() phase. They don't contain any file
logger so no empty spring.log is ever created.

Fixes gh-303
Add docs on initializing a database

Fixes gh-364
Ensure shutdown endpoint is disabled by default

Fixes gh-377