Upgrade PDFBox to 2.0.3
Created by: backslash47
Upgraded to PDFBox 2.0.3.
Needs to disable two tests in GetOriginalDocumentTest because PDFBox has stricter parsing and "original document" from signature is not a valid PDF document (not even in PDFBox 1.8, but 1.8 has lenient parsing). Will be solved if https://issues.apache.org/jira/browse/PDFBOX-3545 fixed.