Add undertow websockets dependency
Resolve placeholders in @ConfigurationProperties prefix
Add missing description
Use wesocket dependency from Undertow starter
Don't resolve ConfigurationProperties placeholders

Revert commit 3ad43e0d445d15f03f92f758ced5ee5c64484806 to give us
a little more time to consider how this will impact tooling.
Polish
Polish
Merge branch '1.1.x'
Guard for null BeanFactory in @ConditionalOnBean

See gh-2080
Merge branch '1.1.x'
Cross-reference "Create a deployable war" how-to

Add a tip for both the Maven and Gradle "Packaging executable jar and
war files" section referring to the how-to.

Fixes gh-2086
Set the default session timeout to 30 mins

Update AbstractConfigurableEmbeddedServletContainer to set the default
session timeout to 30 minutes. Also correct Javadoc to specify that
the default is '30 minutes'.

Fixes gh-2084
Merge branch '1.1.x'

Conflicts:
	spring-boot/src/main/java/org/springframework/boot/context/embedded/jetty/JettyEmbeddedServletContainerFactory.java
Ensure Undertow session timeout is set correctly

Assume that Undertow uses -1 for "no expiry".

See gh-2084
Add formatted version numbers for banner expansion

Add `application.formatted-version` and `spring-boot.formatted-version`
properties for use in banner.txt files. The `application.version` and
`spring-boot.version` properties now return a simple version number
without any formatting.

Fixes gh-2090
Add additional ElementExcludeFilter items

Fixes gh-2088
Polish
Add support for autowired Jackson handlers

Inject the ApplicationContext into Jackson2ObjectMapperBuilder to allow
Jackson handlers to be autowired. See SPR-10768.

Fixes gh-2081
Fix data type of telnet and ssh ports

Define shell.ssh.port and shell.telnet.port as integer properties
so that the generated meta-data exposes the proper type.

Fixes gh-2076
Defer WebApplicationContext initialization

Update SpringBootServletInitializer so that the WebApplicationContext is
not initialized until ServletContextListener.contextInitialized() is
called. This makes it easier to subclass SpringBootServletInitializer
to add additional listeners to be called in a specific order.

Fixes gh-2070