Set of packages to expand fully (ie all groups and modules are displayed)

Initially empty, packages can be added

Property definitions

nitc $ MPackageDot :: mpackages
	# Set of packages to expand fully (ie all groups and modules are displayed)
	# Initially empty, packages can be added
	var mpackages = new HashSet[MPackage]
src/model/model_viz.nit:142,2--144,38