add ínterface for graph generator
Initial interface for {Graph, Node, Edge} creation
basic implementation of graph generator
Initial graph class implementations
A .gitignore for src/
.gitignore for project root
CMake setup
Keep a map of edge and node objects

We need to be able to look these up, given a graphviz type.
A simple graph main function

Just to catch additional errors for now.
fix errors in generator; add generator to build
Graph::contains_edge()
Initial version of read/write routines
Reconstruct our objects at graph load time
Stricter consts
Move edge and node creation to graph member functions
Whitespace and formatting
doc; add asserts
add git ignore list
check if parallel edges are allowed
generator now returns pointer to graph