This package contains classes that are used to manage the programs and graphs
settings. The class GlobalProperties uses the design pattern singelton and
represents the global settings concern the whole program. GraphProperties is
the corresponding class for settings that belong to a graph like for example the
backround color. There is also classes that represents graphical components to
change settings. These implements the interface PropertiesModule so it is
possible to put them inside a settings dialog in an easy way.