Python 3 and QT5 compatibility

[illgenr]

Per issue #6: I've modified the program to use Python3 style print() functions and the QT5 QTWidgets module where necessary. A small tweak was also necessary for the file save dialog - the filename tuple needed an index for some reason.

I made these changes since QT4 is a bit of a pain on Windows. QT5 is a simple pip install.