Gp multi blacklist

Gp multi - small changes by Federico

Fixed single-objective tests to work with gp_multi
Fixed bug on gp with MeanData as mean function, when there was
no initialization

Conflicts:
	limbo.py
	src/cmaes/cmaes.c
	src/limbo/boptimizer.hpp
	src/limbo/gp.hpp
	src/limbo/gp_auto.hpp
	src/limbo/kernel_functions.hpp
	src/limbo/rprop.hpp
	wscript