Fix encoding issues in javadoc

Before this change javadoc in two classes had non-UTF-8 encoded
characters. This caused building Spring API to fail in Java 1.7.

Commit fixes this by replacing wrongly encoded characters with their
UTF-8 equivalents.

Issue: SPR-9097
Merge pull request #35 from sslavic/SPR-9097

* SPR-9097:
  Fix encoding issues in javadoc
Fix javadoc warnings

Before this change there were numerous javadoc warnings being reported
while building Spring framework API.

This commit resolves most of the javadoc warnings, reducing the total
number from 265 to 103.

Issue: SPR-9113
Merge pull request #36 from sslavic/SPR-9113

* SPR-9113:
  Fix javadoc warnings
Convert SpEL plus operands using reg'd converters

Prior to this commit, SpEL's OpPlus ('+' operator) would convert its
left and right operands to String directly via #toString calls.

This change ensures that operand values are delegated to any registered
converters, allowing for customization of the stringified output.

Note that the OpPlus constructor now throws IllegalArgumentException if
zero operands are supplied.

Issue: SPR-8308
Merge pull request #7 from bedla/SPR-8308

* SPR-8308:
  Convert SpEL plus operands using reg'd converters
Fix scoped-proxy memory leak w/ @Resource injection

Prior to this change, request-scoped components having
@Resource-injected dependencies caused a memory leak in
DefaultListableBeanFactory#dependenciesForBeanMap.

Consider the following example:

    @Component
    @Scope(value="request", proxyMode=ScopedProxyMode.TARGET_CLASS)
    public class MyComponent {

        @Resource
        private HttpServletRequest request;

        // ...
    }

The bean name for "MyComponent" will end up being
'scopedTarget.myComponent', which will become a key in
the #dependenciesForBeanMap structure.

On the first request, the injected HttpServletRequest bean will be a
proxy and will internally have a bean name of the form
"$Proxy10@1a3a2a52". This name will be added to the Set value associated
with the 'scopedTarget.myComponent' entry in #dependenciesForBeanMap.

On the second request, the process will repeat, but the injected
HttpServletRequest will be a different proxy instance, thus having a
different identity hex string, e.g. "$Proxy10@5eba06ff". This name will
also be added to the Set value associated with the
'scopedTarget.myComponent' entry in #dependenciesForBeanMap, and this
is the source of the leak: a new entry is added to the set on each
request but should be added only once.

This commit fixes the leak by introducing caching to
CommonAnnotationBeanPostProcessor#ResourceElement similar to that already
present in AutowiredAnnotationBeanPostProcessor#AutowiredFieldElement
and #AutowiredMethodElement. Essentially, each ResourceElement instance
now tracks whether it has been created, caches the ultimate value to be
injected and returns it eagerly if necessary. Besides solving the memory
leak, this has the side effect of avoiding unnecessary proxy creation.

This fix also explains clearly why injection into request-scoped
components using @Autowired never suffered this memory leak: because the
correct caching was already in place. Because @Resource is considerably
less-frequently used than @Autowired, and given that this particular
injection arrangement is relatively infrequent, it becomes
understandable how this bug has been present without being reported
since the introduction of @Resource support in Spring 2.5: developers
were unlikely to encounter it in the first place; and if they did, the
leak was minor enough (adding strings to a Set), that it could
potentially go unnoticed indefinitely depending on request volumes and
available memory.

Issue: SPR-9176
Merge pull request #66 from dridi/SPR-9176

* SPR-9176:
  Fix scoped-proxy memory leak w/ @Resource injection
Fix issue with encoded params in UriComponentsBuilder

The fromUri method of UriComponentsBuilder used uri.getXxx() methods,
which decode the URI parts causing URI parsing issues. The same method
now uses uri.getRawXxx().

Issue: SPR-9317
Javadoc update

Issue: SPR-9265
Add empty location check to ResourceHttpRequestHandler

ResourceHttpRequestHandler now implements InitializingBean and
checks for empty locations.

Issue: SPR-9186
HanderInterceptor and OSIV async request changes

This change updates Open-Session-in-View filters and interceptors for
use in async requests mainly ensuring the open Hibernate session is
unbound from the main request processing thread and bound to the to
async thread.

Issue: SPR-8517
Merge pull request #73 from rstoyanchev/mvc-async

HanderInterceptor and OSIV async request changes
Exception for OSIV deferred close with async requests

OSIV deferred close mode is not supported with async requests and is
unlikely to be what's the desired. This change adds an exception with
a message stating this.

Issue: SPR-8517
Add Jackson 2 HttpMessageConverter and View

Jackson 2 uses completely new package names and new maven artifact ids.
This change adds Jackson 2 as an optional dependency and also provides
MappingJackson2HttpMessageConverter and MappingJackson2JsonView for use
with the new version.

The MVC namespace and the MVC Java config detect and use
MappingJackson2HttpMessageConverter if Jackson 2 is present.
Otherwise if Jackson 1.x is present,
then MappingJacksonHttpMessageConverter is used.

Issue: SPR-9302
Merge pull request #76 from rstoyanchev/jackson2

Add Jackson 2 HttpMessageConverter and View
Pretty print option for Jackson converter and view

Jackson serialization supports pretty printing. Usually it's enabled
by invoking ObjectMapper.configure(..), which is not convenient for
apps with XML configuration. The Jackson HttpMessageConverter and View
now both have a prettyPrint property.

A second more serious issue is documented here:
https://github.com/FasterXML/jackson-databind/issues/12

The workaround discussed at the above link has been implemented.

Issue: SPR-7201
Fix JavaDoc in OpMultiply so that it does not contain special characters

The JavaDoc in OpMultiply contained special characters that caused
problems when building with Java 7 on Mac OS X. The section symbol has
been replaced with the word "Section". Also improved class-level and
method-level JavaDoc in general.
Re-enable ignored tests in MockServletContextTests

Two tests in MockServletContextTests were disabled with @Ignore with the
comment "fails to work under ant after move from .testsuite -> .test";
however, this no longer appears to apply with the Gradle build. Thus
these tests have been re-enabled.
Don't decode URI for content negotiation by extension

Minor bug fix in the ContentNegotiatingViewResolver where decoding the
URI prevented proper detection of the file extension in a URL.

Issue: SPR-9390