Polish spring-context

 - Cache interceptor internals now operate on collections of
   <? extends Cache> instead of <Cache>.
 - Deleted unused imports.
 - Deleted dead code.
 - Suppressed warnings for resource leaks related to not closing
   ApplicationContexts in tests.
 - Suppressed further non-issue warnings in tests.
Add default destination for @SendTo methods

Issue: SPR-11085
Improve logging in spring-messaging

Before this change the amount of logging was too little or too much
with TRACE turned on. This change separates useful debugging
information and logs it under DEBUG and leaves more detailed
information to be logged under TRACE.
Upgrade to reactor-tcp 1.0
Update STOMP decoder to handle incomplete frames

Previously, StompDecoder would throw a StompConversionException when
it attempted to decode a Buffer that contained an incomplete frame.

This commit updates StompDecoder to return null when it encounters an
incomplete frame. It also resets the buffer, thereby allowing the
decode to be reattempted once more data has been received.
StompCodec's decoder function has been updated to stop attempting to
decode a Buffer when StompDecoder returns null.

Issue: SPR-11088
Polish STOMP codec

Issue: SPR-11088
Ignoring non-loadable annotations in SourceClass.getAnnotations() and therefore in the collectImports algorithm

Issue: SPR-11086
Upgraded to JSF 2.0 baseline; building against JSF 2.2 now
Introduced getBeanNamesForAnnotation method on ListableBeanFactory

Issue: SPR-11069
Upgraded to JCache 1.0 PFD
Rename @SubscribeEvent to @SubscribeMapping

Also @SubscribeMapping is now a method-level annotation only that can
be used in combination with a type-level @MessageMapping.

This method also documents supported method arguments and return value
types on @Subscribe- and @MessageMapping methods.
Polish Javadoc for ListableBeanFactory
Fix broken javadoc links in reference guide

Replace links in the reference documentation from
`http://static.springsource.org/spring/docs/current/api/..` to
`http://docs.spring.io/spring/docs/current/javadoc-api/..`

Issue: SPR-11087
Replace non UTF-8 characters in asciidoc source

Replace the odd instance of non UTF-8 characters in the reference
asciidoc source, mainly smart-quotes.

Issue: SPR-11096
Add .gradletasknamecache to .gitignore
Replace springsource.org links with spring.io

Update reference documentation links to use the new spring.io domain.

Issue: SPR-11096
Wrap reference asciidoc at 90 characters

Reformat the asciidoc source for the reference guide to wrap at about
90 characters.

Issue: SPR-11096
Replace asciidoc authors convention with attribute

Replace the second line of the asciidoc reference guide that, by
convention, specifies authors with an 'author' explicit attribute.

Issue: SPR-11096
Specify asciidoc type

Specify a specific asciidoc type of 'docbook' to prevent
'multiple titles at level 0' errors during generation.

Issue: SPR-11096
Remove superfluous space before 'http' in asciidoc

Remove the superfluous space that appears before each 'http' reference
in the asciidoc source. Presumably there due to some quirk of the
docbook conversion.

Issue: SPR-11096