Provide links to the detailed documentation in README
Merge pull request #1 from multani/link-to-documentation

Provide links to the detailed documentation in README
Move tests to a tests/ subpackage
Fix filtering tests with negative ("!") patterns

Fixes: https://bugs.launchpad.net/zope.testrunner/+bug/1160965
Use new filtering mechanism on modules
Use new filtering mechanism on layers
Add unit tests for the filtering function
Add Changelog entry
Note change.
Merge multani-fix-filtering branch.
Made python -m zope.testrunner work again

This used to work with old Python versions (2.5?  2.4?), when
python -m package used to run package/__init__.py as a script.  Modern
Pythons (2.6, 2.7, 3.x) look for package/__main__.py instead.
Make tests pass again when subunit can't be imported.