Added a PHP_CodeSniffer review.

See http://pear.php.net/package/PHP_CodeSniffer for more information.

Uses the csv report format to easily parse the results. Default
standard is PEAR, but this can easily be changed by calling `setStandard`
on the review.

Usage of `setStandard` can be seen in the new static-review-pre-commit.php
hook, where it uses the PSR2 standard. Interally this just adds the
`--standard=?` option to the `phpcs` command line process call.