Allow for SpEL expressions in initial-delay attribute

Issue: SPR-10102
Added MappingJackson2MessageConverter for JMS

Issue: SPR-10099
JmsTemplate uses configured receiveTimeout if shorter than remaining transaction timeout

Issue: SPR-10109
Fixed AbstractAutoProxyCreator to accept null bean names again

Issue: SPR-10108
Fixed QualifierAnnotationAutowireCandidateResolver's detection of custom qualifier annotations

Issue: SPR-10107
Initial preparations for 3.2.1
Fix GenericConversionService search algorithm

Previously the algorithm used by GenericConversionService to find
converters incorrectly searched for interfaces working up from the
base class. This caused particular problems with custom List
converters as as the Collection interface would be considered before
the List interface giving CollectionToObjectConverter precedence
over the custom converter.

The updated algorithm restores the class search order to behave in the
same way as Spring 3.1.

Issue: SPR-10116
Backport-Issue: SPR-10117
Backport-Commit: aa914497dc312568cc541e53302038729364ce68
Add spring-oxm-1.5.xsd

Issue: SPR-10121
Update contributor guidelines regarding 3.2.x branch
Support snapshot versions qualified by branch name
Merge branch 'SPR-10124' into cleanup-3.2.x

* SPR-10124:
  Support snapshot versions qualified by branch name
Various updates to support IDEA

Remove the 'final' modifier from SingletonBeanFactoryLocatorTests
to work around the "cannot extend final class" error issued when
running all tests. The error was due to confusion with IDEA between
the two variants of SingletonBeanFactoryLocatorTests across
spring-context and spring-beans.

Rename one of the GroovyMessenger classes to GroovyMessenger2.
Previously there were multiple Groovy classes named
'GroovyMessenger', causing a compilation error in certain IDE
arrangements.

Update import-into-idea.md documentation

Add various IDEA artifacts to .gitignore
 - ignore derby.log wherever it is written
 - ignore IDEA's test-output directory
 - ignore IDEA's Atlassian connector config file
Remove trailing whitespace in source files

  find . -type f -name "*.java" -or -name "*.aj" | \
    xargs perl -p -i -e "s/[ \t]*$//g" {} \;

Issue: SPR-10127
Replace space indentation with tabs

Issue: SPR-10127
Merge branch 'SPR-10127' into cleanup-3.2.x

* SPR-10127:
  Replace space indentation with tabs
  Remove trailing whitespace in source files
Fix various Javadoc warnings

Issue: SPR-10128
Replace <code> with {@code} throughout Javadoc

Issue: SPR-10128
Merge branch 'SPR-10128' into cleanup-3.2.x

* SPR-10128:
  Replace <code> with {@code} throughout Javadoc
  Fix various Javadoc warnings
Fix warnings due to unused import statements
Fix [varargs] compiler warnings

Remove unnecessary 'null' argument from calls to vararg supported
methods and fix cast in ValidationUtils.invokeValidator().