Change gopivotal.com to pivotal.io

This commit changes email addresses and URLs so that they point to
pivotal.io instead of gopivotal.com.
JavaMailSenderImpl catches Exception instead of MessagingException and checks for reconnect in case of message batches

Issue: SPR-12298
Further locking optimizations for the retrieval of non-singleton beans

Issue: SPR-12250
Provider declaration for @Value method argument works again

Issue: SPR-12297
JsonPath dependency upgraded to 1.1

Issue: SPR-12299
Consistent reset of resource holders on doBegin failure

Issue: SPR-12280
Comprehensive revision of SpEL's bytecode generation and number handling (BigInteger support, doubleValue fallback)

Issue: SPR-9913
Polishing
Fix reference code sample
Fix outdated references to JobDetailBean

Issue: SPR-12306
TextMessage.toString() does not throw StringIndexOutOfBoundsException for payload with multibyte characters

Issue: SPR-12307
WebSocketSession extends java.io.Closeable, plus reorganization of AbstractSockJsSession's code

Issue: SPR-12311
Explicitly detect (and prevent) private @Scheduled methods on CGLIB proxies

Issue: SPR-12308
Consistent use of LinkedHashSet for interfaces (since interface order may matter in subtle cases)
Add shortcuts for Jackson mix-in annotations registration

This commit adds support for direct Jackson mix-in annotations registration in
Jackson2ObjectMapperFactoryBean and Jackson2ObjectMapperBuilder.

Issue: SPR-12144
Add (de)serializerByType() and mixIn() to Jackson2ObjectMapperBuilder

Issue: SPR-12313
Add Vary:Origin HTTP header in SockJS responses

This change adds a "Vary: Origin" HTTP response header for /info and
/iframe SockJS endpoints.
This is preventing proxies and browsers from caching a response and
reusing it for an invalid Origin.

Reference: https://groups.google.com/forum/#!topic/sockjs/svsLWRorSis

Issue: SPR-12310
SockJs client: add an XhrTransport for Undertow

This change adds a new XhrTransport for the SockJs client
implementation. This transport is based on `UndertowClient`,
Undertow's HTTP client.

Note that this transport can be customized with an OptionMap that is
used by the Xnio worker backing the I/O communications (see
http://xnio.jboss.org).

Implementation tested with undertow 1.0.36, 1.1.0.RC3, 1.2.0.Beta1.

Issue: SPR-12008
Polish indentation
Allow binary messages in StompSubProtocolHandler

Issue: SPR-12301