* add XSD element for nested router type
* add tests on the matter
* polishing for RouterParserTests
JIRA: https://jira.springsource.org/browse/INT-2893
INT-2893: Polishing
INT-2893: after rebasing to 3.0
XSD changes reverted from 2.2 and moved to 3.0
INT-2893 Polishing
Factor out common elements; fixing missing documentation for
`expression` within a `router` within a `chain`.
Copy schemas, cleanup whitespace, update spring.schemas files,
update version in AbstractIntegrationNamespaceHandler.
For each schema compared the 2.2 version with the 3.0 version
(diff -w), ensuring the only difference is the import of
3.0 schemas (where appropriate) instead of 2.2.
Add 2.2 versions of module schemas.
JMX is already covered by an existing pull request.
INT-2536 Schema Check
Bump version for schema check in
AbstractIntegrationNamespaceHandler.
INT-2536 Remove Schema Versions
Some test config files had 2.1 versioned schemas.
