Make FFTW3 mandatory
Geodesic refactoring: new Field class = Bitmap<double>
Geodesic refactoring: proper constructor of the random field
Geodesic refactoring: QG class containing direction as d
Stop special-casing Bitmap<Color>
Move stuff from Bitmap to Array
Separate Array definition into a proper header
Geodesic refactoring: use the new class Array<coo>
Move the iterator stuff to Array