suppressed Navigator._window.url changes on fetch handling
(cherry picked from commit d9afd5c)
changed is_pdf query to search for PDFs magic number in the first 1024 bytes. reference: http://www.decalage.info/file_formats_security/pdf [Main security issues -> Parser "flexibility"]
(cherry picked from commit cd5a457)
Merge pull request #57 from florianschmitt/pullRequest

Pull request