Note: this is a modified version of dompdf, as follows (search ZBSMOD in directory for your ease)
- Removes font files (to trim size, we're using our own)
- Remove 'sample-fonts' directory from bundled php-font-lib
- Remove 'tests' directory from bundled php-font-lib + phpunit file
- Remove 'tests' directory from bundled php-css-parser + phpunit file