First revision of a class that builds a graph from an image's history and can perform algorithms using the Boost Graph library.

- the file imagehistorygraph_boost.h is internal and contains all code directly using the boost library
- the file imagehistorygraphdata.h implemented the internal shared data, which is a Graph with custom properties for each vertex and egde
- the file transitive_reduction.hpp is copied from the boost distribution with the exception of replacing one ";" by "," in line 103, making it compile