PHPCoverage Code

- Added ability to merge remote coverage recordings.
- Changed driver.php options
- Updated changes and release notes.
- Added PEAR XML_Parser module (stripped down version).
- Added common xdebug binaries for easy installation.

- Fixed code to avoid instrumenting a file twice.
- Fixed typo with LOCAL_PHPCOVERAGE_LOCATION

- Added initial version of PHPCoverage from trunk