Issue: SPR-4365

Issue: SPR-13275

SpringJUnit4ClassRunner, SpringClassRule, and SpringMethodRule now
throw an IllegalStateException with a meaningful message if JUnit 4.9
is not present in the classpath (specifically if
org.junit.runners.model.MultipleFailureException cannot be loaded).

Issue: SPR-13521

In order to simplify configuration of the SpringMethodRule and to ensure
that the correct TestContextManager is always retrieved for the
currently executing test class, this commit introduces a static
TestContextManager cache in SpringClassRule.

In addition, since it is not foreseen that SpringClassRule and
SpringMethodRule should be able to be subclassed, their internal methods
are now private instead of protected.

Issue: SPR-7731

Since Spring Framework 2.5, support for integrating the Spring
TestContext Framework (TCF) into JUnit 4 based tests has been provided
via the SpringJUnit4ClassRunner, but this approach precludes the
ability for tests to be run with alternative runners like JUnit's
Parameterized or third-party runners such as the MockitoJUnitRunner.

This commit remedies this situation by introducing @ClassRule and @Rule
based alternatives to the SpringJUnit4ClassRunner. These rules are
independent of any Runner and can therefore be combined with
alternative runners.

Due to the limitations of JUnit's implementation of rules, as of JUnit
4.12 it is currently impossible to create a single rule that can be
applied both at the class level and at the method level (with access to
the test instance). Consequently, this commit introduces the following
two rules that must be used together.

 - SpringClassRule: a JUnit TestRule that provides the class-level
   functionality of the TCF to JUnit-based tests

 - SpringMethodRule: a JUnit MethodRule that provides the
   instance-level and method-level functionality of the TCF to
   JUnit-based tests

In addition, this commit also introduces the following new JUnit
Statements for use with rules:

 - RunPrepareTestInstanceCallbacks

 - ProfileValueChecker

Issue: SPR-7731