start using libformfactor

Polyhedron, associated classes, and some tests moved to external library.

Sample/Lattice/Lattice3D.cpp

@@ -85,8 +85,7 @@ std::vector<R3> Lattice3D::reciprocalLatticeVectorsWithinRadius(const R3 q, doub
     for (int index_X = -max_X; index_X <= max_X; ++index_X) {
         for (int index_Y = -max_Y; index_Y <= max_Y; ++index_Y) {
             for (int index_Z = -max_Z; index_Z <= max_Z; ++index_Z) {
-                I3 coords(index_X + nearest_coords.x(), index_Y + nearest_coords.y(),
-                          index_Z + nearest_coords.z());
+                I3 coords = I3(index_X, index_Y, index_Z) + nearest_coords;
                 if (m_selection_rule && !m_selection_rule->coordinateSelected(coords))
                     continue;
                 R3 latticePoint = coords.x() * m_ra + coords.y() * m_rb + coords.z() * m_rc;