made acquisition_functions a python package
gp_test: added test for drawing joint samples
pmin_discretization: fixed a small bug (iteration was one too short)
pmin_discretization_test: little function to see the chosen representer points
gp_model: implemented drawJointSample() and removed draw()
entropy_search: now multiple minima can be dealt with
hyper_parameter_sampling: outsourced the hyper-parameter sampling
OptSizeChooer:
1)removed hyper-parameter sampling
2)enabled multi-processing