source files: current.lsp
The `current' object is a central repository for global information. It provides other objects with names for the current model, contour, image, etc.
Initially I put this in to minimize the number of global variables that would need to be hard-coded into object classes. At the moment, the `current' object is still treated as a global variable; a better approach might be to specify it when creating new objects which need to reference other global objects.