moved RandomNumberGenerator from Simulator to World
Merge commit '0b4b573c21e73c811b3a1c45a3043697b7f16ffe'

Conflicts:
	bd/BDSimulator.hpp
	bd/BDWorld.hpp
	bd/samples/hardbody/main.cpp
	bd/samples/hardbody/wscript
	bd/tests/BDSimulator_test.cpp
	bd/tests/BDWorld_test.cpp
	bd/tests/wscript