All tests can be run from the root of the package by running:
$ phpunit

Tests classes are divided into groups which can be run individually:
$ phpunit --group main
$ phpunit --group appenders
$ phpunit --group configurators
$ phpunit --group filters
$ phpunit --group helpers
$ phpunit --group layouts
$ phpunit --group renderers

Individual test classes can be run using e.g.:
$ phpunit src/test/php/appenders/LoggerAppenderSocketTest.php

Do not use relative file paths in the tests. Absoulte paths may be constructed
using snippets like:
* dirname(__FILE__) . '/../path/to/file' 
* PHPUNIT_TEMP_DIR . '/../path/to/file'
