Added PDF to QIF converter as provided by Volker Paul.

"The "ACcount STatement to QIF converter" acst2qif.py, a free Python script,
takes account statements in PDF, converts them to text using pdftotext and
extracts data from this text. The converter needs to be configured by a
configuration file that resides by default in $HOME/.acst2qif.cfg.

Documentation about the converter is in its sourcecode and the
configuration file (example) also contains its own documentation.
The converter needs Python and pdftotext. Its results are to be
imported in KMyMoney or other software that accepts QIF input."