Fix unit tests

PHPUnit 4.3.1 by Sebastian Bergmann.

Configuration read from /home/fox/src/php/ezsystems/zetacomponents/MvcTools/phpunit.xml.dist

...............................................................  63 / 168 ( 37%)
............................................................... 126 / 168 ( 75%)
..........................................

Time: 5.78 seconds, Memory: 11.75Mb

OK (168 tests, 352 assertions)

What's the reason for "prefer-source" ?