Ported from Qt4 to Qt5

Thanks to the excellent docs!
http://qt-project.org/doc/qt-5.0/qtdoc/cmake-manual.html
http://qt-project.org/doc/qt-5.0/qtdoc/portingguide.html
Use QAction::triggered because QAction::activated is from Qt3

and it stopped working in Qt5
Use new signal connection syntax

which is checked at compile time
http://qt-project.org/doc/qt-5.0/qtdoc/qt5-intro.html#new-connection-syntax
ignore the build/ directory
Removed unused ancient dependencies.
bump
Merge pull request #6 from mvidner/qt5-port

Ported from Qt4 to Qt5