bbo implemented in python also

C++ (only modules src/bbo/ and src/dmp_bbo/ have been changed)

• moved Task/TaskSolver from bbo/ to dmp_bbo/
• costFunction()/performRollout() take only one sample/rollout now
• Some renaming to avoid long names: runEvolutionaryOptimization => runOptimization
• runOptimizationParallel is deprecated, a simpler version will be available soon
• due to the changes above, the interface has changed (only affects modules src/bbo/ and src/dmp_bbo/)

Python

• src/bbo/ and src/dmp_bbo/ implemented in Python also (see python/bbo and python/dmp_bbo)
• everything is compatible with both python2.7 and python3
• complete overhaul of plotting in Python
• enabled step-by-step rollouts and updating, which facilitates working with real robots (see the related Doxygen documentation page python/dmp_bbo/demos/demo_optimization_one_by_one.bash for a demo)