GrInvIn for graph theory teaching and research

The GrInvIn framework provides the core functionality needed to implement an application for graph theory in general. It includes basic functionality to work with graphs, invariants, and conjectures. In addition to data structures and interfaces for these concepts, the framework also provides a basic graph editor, various invariant computing routines, and an intuitive graphical user interface. GrInvIn is still being developed and soon further functionality (such as graph generation programs) will be added.