Fixed the way PHPUnit_Util_Configuration parses listener constructor arguments

Previously, getListenerConfiguration assumed the <arguments> element
would always be the second element (index 1) because nicely formatted
XML has a DOMText node containing a newline and some space before the
arguments node. Computer-generated XML places the arguments element
immediately after the listener element, so the node would be at index 0,
causing the arguments node to not be found. Instead, it now searches
the entire listener node for argument nodes.
Merge pull request #594 from austinhyde/listener-arguments-fix
Remove duplicate description of --debug flag
Merge pull request #601 from joncave/debug-help
Fixed tests on windows
Fixed tests on windows
Fix data serialization when using process isolation (closes #614)
Merge pull request #616 from fabpot/isolation-fix
Prepare release.
Added a small 'Contributing' section to the README.
Add maximum supported version dependency information.
Add maximum supported version dependency information.