BATCH-2195: Document Spring Batch Integration

* Removed APT files
* General formatting and spelling fixes
* Converted README.md to docbook
* Expanded converted README.md docs to include usable code snippets
Removed serialisable check on ExecutionContext entries

The serialisation/deserialisation implementation is injectable, so it does not make sense to enforce the presence of this interface
Updated Spring Batch Integration to use Spring Integration 4.0.0.RC1
Add basic JSR-352 configuration samples

* Inline class references
* batch.xml references
* Spring bean references
BATCH-2011: Updated javadoc to conform to java.lang.Comparable
BATCH-2042: Updated documentation to call out the need for a fault tolerant ItemProcessor to be idempotent
BATCH-2090: Undeprecated HibernateItemWriter#doWrite(SessionFactory sessionFactory, List<? extends T> items)
BATCH-2060: Fixed Github links
fix for BATCH-2106
BATCH-2092: Added access to line input when an exception is thrown
BATCH-2083: Improved logging detail in AbstractStep
BATCH-2085: Updated documentation to reflect current flow configuration options
BATCH-2185: Updated to support annotation based listener configuration via javaconfig
BATCH-2016: Added new flag to indicate if the step is being executed on
a restart.  If it is, the transition will be followed.  If not, we'll
look to see if we should be looking for somewhere else to restart.
BATCH-2189: Wrapped checked exception with a custom RuntimeException to follow rules for @PostConstruct
BATCH-1786: Added type to AbstractJobExplorerFactoryBean so that a cast isn't required on getObject()
BATCH-2172: Fixed database version check for DB2ZOS
BATCH-2204: Updated StepParserStepFactoryBean to set the buffered flag correctly when building a fault tolerant step
Update version literals prior to release 2.2.6
[maven-release-plugin] prepare release 2.2.6.RELEASE