do not blindly overwrite configuration files

[SebastianS90]

closes #153
closes #130

[taylorotwell]

Instead of all this why not just use a try / finally or something?

[SebastianS90]

@taylorotwell try-finally does not always help:

finally.php:

<?php
try {
	sleep(10);
} finally {
	echo "Finally!\n";
}

sebastian@seb-pc ~ % php finally.php 
^C
130 sebastian@seb-pc ~ %

Finally does not execute when pressing Ctrl+C

And finally would not help to preserve a custom phpunit.dusk.xml either. Can you please merge it or point me to a different solution for both bugs?