Added in memory cache layer
Merge branch 'master' of git://github.com/sixty-nine/DrupalTesting into swap_cache_nowhitespace

Conflicts:
	src/Liip/Drupal/Testing/Test/DrupalTestCase.php
#6 Added tests, updated .xml.dist
Better documentation in phpunit.xml.dist
Merge pull request #6 from andreiashu/swap_cache_nowhitespace

Added in memory cache layer