Made workspace a subclass of QGraphicsScene

This way we can inherit certain events
Moved some events around
	modified:   IntelliGraph.pro
	modified:   edge.h
	modified:   node.h
	new file:   popup.cpp
	new file:   popup.h
	new file:   popup.ui
	modified:   workspace.cpp
	modified:   workspace.h
Added class and ui for Popup.
	modified:   IntelliGraph/popup.cpp
	modified:   IntelliGraph/popup.h
	modified:   IntelliGraph/popup.ui
Modified the Popup so it cannot resize