- removed dependency on pdfminer.six - library does not allow saving password protected pdfs
- added internal copy of pypdf2
- an internal pdf-annotation port has been added to conveniently create annotations
- new parameters for signing pdf documents:
'sigflagsft' - annotation flags
'password' - for password encypted documents
- dictionary key names for pdf signing are now strings, not bytes
- the values of the pdf signing dictionary that were bytes are now strings
- the dictionary value for the 'signature' key must match latin1 encoding,
other encodings are not supported