version 0.4.3 (SH Dec 26 2019)
- whitespace fixes
- allow showing 16bit grayscal pngs
- some code cleaning

version 0.4.2 (SH Dec 19 2019):
- use get/set consistently for configuration module
- fix bug not showing last remaining photo
- added some tool tips to inform about hashing values

version 0.4.1 (SH Dec 17 2019):
- small bugs in the requirements specifications
- added NEWS file

version 0.4 (SH Dec 16 2019):
- first functional version uploaded to PyPi

