Changed Enclosed runner to ignore abstract classes. Before this change, an abstract enclosed class caused jUnit to throw an exception.
Implemented the changes proposed davidhart82
Changed the filtered collection to an ArrayList from an HashSet to avoid re-ordering of
existing order-dependant test suites, as per the comments of kcooney.
Implemented the changes proposed by kcooney:

1) Now passing classes.length to the constructor of ArrayList
2) Code style adjustment (no spaces before the = in an assignment)
Continues Issue 296: TestWatchman.failed should not be invoked for AssumptionViolatedExceptions
see https://github.com/KentBeck/junit/issues/296

The solution introduced breaks with the general concept of the TestWatcher which is to call a
tracing method for any state the test reaches.

This commit introduces a new method skipped() to the TestWatcher. Quirk: The AssumptionViolatedException
is in package "internal".
Remove wildcard imports.
Fixes #355 Improve Assume to allow custom message
Workaround for compilation problem on non-recent JDKs.

Fixes #474.
Use org.junit.Assert instead of junit.framework.Assert
Merge remote branch 'remotes/upstream/master'

Conflicts:
	src/test/java/org/junit/tests/experimental/rules/TestRuleTest.java
Adjust dependencies as retrieved from KentBeck / junit : master
Merge pull request #489 from matthewfarwell/assume-message

Fixes #355 Improve Assume to allow custom message
Merge pull request #490 from marcphilipp/remove-usage-of-old-assert

Use org.junit.Assert instead of junit.framework.Assert
Merge pull request #491 from marcphilipp/fix-issue-474

Workaround for compilation problem on non-recent JDKs
Merge pull request #457 from mmichaelis/master

Add trace method "skipped" to TestWatcher
Description.getTestClass() did not work reliably.
Was assuming that the ClassLoader used for JUnit could also load test classes.
While this may be true in a simple test runner based on a flat classpath, it is not true in all test runners.
When we are given a Class object, keep it—do not try to reconstruct it from its name alone.
https://github.com/KentBeck/junit/pull/498 review comments.
Reorder assignments to match order of parameters.
Varargs makes test slightly shorter.
Make getClassName more reliable when fTestClass defined.