uniform variable name n_, not nbr_ or num_

Base/Math/IntegratorMCMiser.h

Img3D/Build/PositionBuilders.cpp

Param/Distrib/DistributionHandler.cpp

Param/Distrib/DistributionHandler.h

Param/Distrib/Distributions.cpp

Param/Distrib/Distributions.h

Param/Distrib/ParameterDistribution.cpp

Param/Distrib/ParameterDistribution.h

Sim/Simulation/ISimulation.cpp

Sim/Simulation/ISimulation.h

Tests/Unit/Param/DistributionsTest.cpp

Tests/Unit/Param/ParameterDistributionTest.cpp

auto/Wrap/libBornAgainParam.py

auto/Wrap/libBornAgainParam_wrap.cpp

auto/Wrap/libBornAgainSim.py

auto/Wrap/libBornAgainSim_wrap.cpp