Update to handle newer Qt versions

Merge pull request #13 from sucksome/master

Modularize screen keyboard implementation

Added icons contributed by Juan Lasca

There were no icons other than some low resolution .xpm files, so he took the liberty of preparing some svg icons and a script (requires the imagemagick package) to generate pngs of multiple resolutions (suitable for use with a .desktop desktop entry file or in the application).

Merge pull request #2 from halexus/master

Screen Keyboard now also works when opening a file

Merge pull request #1 from halexus/master

Add virtual keyboard window with logic operations

Remove some entries that may confuse acceptance