Revision control
++ QT += widgets
++
++ HEADERS += \
++ edge.h \
++ node.h \
++ graphwidget.h
++
++ SOURCES += \
++ edge.cpp \
++ main.cpp \
++ node.cpp \
++ graphwidget.cpp
++
++ # install
++ target.path = $$[QT_INSTALL_EXAMPLES]/widgets/graphicsview/elasticnodes
++ INSTALLS += target