Fixed XML::load() does not report libxml errors on Windows.
Fixed XML::load() fails to load relative XInclude paths on Windows.
Exclude system temp directory in stack traces on Windows.

PHPUnit_Util_PHP_Windows writes the process isolation script template into the Windows TEMP directory and loads the script by including the file, which causes an extraneous last stack frame in all test results on Windows.
Fixed PHPT file path expectations fail on Windows.
Include process isolation file prefix to avoid false-positive matches.
Merge pull request #1354 from sun/win-fail

PHPUnit test suite fails on Windows