Changed namespace of C++ code to bob::learn::misc.

bob/learn/misc/cpp/BICMachine.cpp

bob/learn/misc/cpp/BICTrainer.cpp

bob/learn/misc/cpp/EMPCATrainer.cpp

bob/learn/misc/cpp/GMMMachine.cpp

bob/learn/misc/cpp/GMMStats.cpp

bob/learn/misc/cpp/GMMTrainer.cpp

bob/learn/misc/cpp/Gaussian.cpp

bob/learn/misc/cpp/IVectorMachine.cpp

bob/learn/misc/cpp/IVectorTrainer.cpp

bob/learn/misc/cpp/JFAMachine.cpp

bob/learn/misc/cpp/JFATrainer.cpp

bob/learn/misc/cpp/KMeansMachine.cpp

bob/learn/misc/cpp/KMeansTrainer.cpp

bob/learn/misc/cpp/LinearScoring.cpp

bob/learn/misc/cpp/MAP_GMMTrainer.cpp

bob/learn/misc/cpp/ML_GMMTrainer.cpp

bob/learn/misc/cpp/PLDAMachine.cpp

bob/learn/misc/cpp/PLDATrainer.cpp

bob/learn/misc/cpp/WienerMachine.cpp

bob/learn/misc/cpp/WienerTrainer.cpp