This commit migrates all remaining tests from JUnit 3 to JUnit 4, with
the exception of Spring's legacy JUnit 3.8 based testing framework that
is still in use in the spring-orm module.

Issue: SPR-13514

Issue: SPR-13399

Issue: SPR-13312

Issue: SPR-13312

Issue: SPR-13312

Issue: SPR-13300

Issue: SPR-13221

XML parsing tests pass on non-English locales now, plus a revised exception message and some minor polishing

Issue: SPR-13136
(cherry picked from commit 38b8262e)

Issue: SPR-13136

Issue: SPR-13129

Issue: SPR-12926

(cherry picked from commit f9339417)

Issue: SPR-12578

Issue: SPR-12383

Commit b676c418 should have added the 4.1 XSDs for the jdbc and oxm
modules.

Issue: SPR-12011

Issue: SPR-11768

(cherry picked from commit c97c2469)

Issue: SPR-11737
(cherry picked from commit 93d13cfc)
(cherry picked from commit 4196e6c9)

Issue: SPR-11702

Issue: SPR-11635
(cherry picked from commit f7a17add)

Issue: SPR-11635

Issue: SPR-11635

Improved the SAX to StAX (and vice-versa) bridge exposed via StaxUtils.
The old integration had some issues with namespace declaration
attributes, brought to light in a XMLUnit upgrade.

Issue: SPR-11549

Revised ResizableByteArrayOutputStream as an actual subclass of ByteArrayOutputStream, and consistently applied appropriate ByteArrayOutputStream initial capacities across the codebase

Issue: SPR-11594

Prior to this commit, the codebase was using a mix of log4j.xml
and log4j.properties for test-related logging configuration. This
can be an issue as log4j takes the xml variant first when looking
for a default bootstrap configuration.

In practice, some modules declaring the properties variant were
taking the xml variant configuration from another module.

The general structure of the configuration has also been
harmonized to provide a standard console output as well as an
easy way to enable trace logs for the current module.

Update OXM AbstractMarshaller to support processing of external
XML entities. By default external entities will not be processed.

Issue: SPR-11376

- Consistent importing of org.junit.Assert.*;
- Proper declaration of expected exceptions via @test(expected).
- Renamed SpEL ExpressionTestCase to AbstractExpressionTests.
- Formatting and test method naming conventions.

Corrected documentation regarding the CatchAllConverter in the XStream
javadocs.