restore dependence on external libformfactor

Doc/FFCatalog/FFCatalog.pdf

Doc/FFCatalog/FormFactors.tex

Sample/CMakeLists.txt

Sample/HardParticle/IFormFactorPolyhedron.cpp

Sample/HardParticle/IFormFactorPolyhedron.h

Sample/HardParticle/IFormFactorPrism.cpp

Sample/ff/Factorial.h

Sample/ff/PolyhedralComponents.cpp

Sample/ff/PolyhedralComponents.h

Sample/ff/PolyhedralTopology.h

Sample/ff/Polyhedron.cpp

Sample/ff/Polyhedron.h

Sample/ff/Prism.cpp

Sample/ff/Prism.h

Tests/Unit/Numeric/FormFactorSpecializationTest.cpp

Tests/Unit/Numeric/FormFactorSymmetryTest.cpp

Tests/Unit/Sample/FactorialTest.cpp

auto/Wrap/doxygenSample.i

cmake/BornAgain/Dependences.cmake