blurry user interface on retina osx

[petri.p...@gmail.com]

Hey,

Does anyone know why Mnemosyne is blurry on MacOS (retina display)? If someone can point me to right direction I might find time to contribute fix to the project, of course depending on amount of effort required.

Issue illustrated: http://i.imgur.com/RlWMGeA.png

- Petri

[thew...@gmail.com]

As noted by Qt5 documentation about [high DPI](http://doc.qt.io/qt-5/highdpi.html):

> Note: On macOS, high-DPI support is enabled by settings in the Info.plist file. Make sure they are present.

>> <key>NSPrincipalClass</key>
>> <string>NSApplication</string>
>> <key>NSHighResolutionCapable</key>
>> <string>True</string>