CacheAspectSupport checks Cache.get(key) once per invocation only

Issue: SPR-11592
Fixed SPR issue reference and aligned exception messages

Issue: SPR-11592
Update SockJS overview section and polish
Revise section explaining the flow of STOMP messages
Add doc section on configuration and performance

Issue: SPR-11450
Next development version
Revert "Next development version"

This reverts commit 4788875a4b627f615f7e496dd18ad222e981d34e.
AbstractApplicationEventMulticaster only caches if event type and source type are cache-safe

Issue: SPR-11606
Relaxed getElementTypeDescriptor assertion to not insist on a ResolvableType-known array

Issue: SPR-11608
Fix typo in documentation
Provide more accurate error message
Revert "Improve suffix pattern check"

This reverts commit 3474afb165b6efa1a15db87c088e0fe79353000f.

Unfortunately this change is likely to cause issues for applications
that use regular expressions in a URI variable. I think we will have
to leave at: if there are any dots in the last segment of the
request path, regardless of whether they're in a URI var or not,
the suffix pattern match is off.

Issue: SPR-11532
Maintenance version updates, excludes for overlapping dependencies (PR #499)
Correctly resolve accessors for static properties on Class

Issue: SPR-11609
Consistent PropertyAccessor method order as declared in the interface

Issue: SPR-11609
Document better ASYNC dispatch type config for Filters

Although the need to map the ASYNC dispatcher type to a Filter was
already mentioned, it wasn't very prominent and can be quite critical
in some cases. This change addresses that.

Issue: SPR-10440
Improve doc on authentication for stomp/websocket
Consider a null ClassLoader (typically the bootstrap CL) as cache-safe

Issue: SPR-11606
(cherry picked from commit a4a2e80)
Next development version
Switch master to 4.1.0.BUILD-SNAPSHOT