Remove mention of AUTHORS file from copyright.

COAST/COASTProcess.cc

COAST/COASTProcess.h

COAST/COASTStack.h

COAST/COASTUserLib.cc

COAST/ParticleConversion.cc

COAST/ParticleConversion.h

Documentation/Examples/boundary_example.cc

Documentation/Examples/cascade_example.cc

Documentation/Examples/cascade_proton_example.cc

Documentation/Examples/geometry_example.cc

Documentation/Examples/helix_example.cc

Documentation/Examples/logger_example.cc

Documentation/Examples/particle_list_example.cc

Documentation/Examples/stack_example.cc

Documentation/Examples/staticsequence_example.cc

Documentation/Examples/stopping_power.cc

Documentation/Examples/vertical_EAS.cc

Environment/BaseExponential.h

Environment/DensityFunction.h

Environment/Environment.h