rm class and source files IDecoratableBorn

Sample/Particle/FormFactorCrystal.h

Sample/Scattering/DecoratedFF.h

Sample/Scattering/IDecoratableBorn.cpp

Sample/Scattering/IDecoratableBorn.h

Sample/Scattering/IFormFactor.h

Tests/SingleUse/ff-tetrahedron.cpp

Tests/Unit/Numeric/BisectFF.cpp

Wrap/Swig/libBornAgainCore.i

Wrap/Swig/libBornAgainResample.i

Wrap/Swig/libBornAgainSample.i

auto/Wrap/doxygenSample.i

auto/Wrap/libBornAgainCore_wrap.cpp

auto/Wrap/libBornAgainSample.py

auto/Wrap/libBornAgainSample_wrap.cpp

auto/Wrap/libBornAgainSample_wrap.h