- Add a way to set the minimum PDF version
- Add a way to force the PDF version
- Have isEncrypted return true if an /Encrypt dictionary exists even
when we can't read the file
- Allow qpdf_init_write to be called multiple times
- Update some comments in headers
git-svn-id: svn+q:///qpdf/trunk@748 71b93d88-0707-0410-a8cf-f5a4172ac649