Resolve issue #9 and convert to Qt5

[netbomo]

I've done some small things :

• Built with QT 5.7.
• Change #includes (Qwidget is a separate module)
• Remove QApplication::UnicodeUTF8 in QApplication::translate method (read Qt forum)
• add QDir::homePath() + in file name string in mainwindow.cpp in order to be able to save csv and png in home directory
• add coordonateX(0) and spinPoints->value() in PNG name in order to be able to save multiple PNG from the same dataset with different zoom or drag
• remove PNG export disable in order to allow export PNG after stop or pause

I hope you will find it usefull and working on windows

cheers

[netbomo]

@CieNTi : I hope you will enjoy with this small tricks.