added check vs negative in bounding_box, added set method for width, length and height that checks vs negative values
added check vs negative in bounding_box, added set method for width, length and height that checks vs negative values

cburbridge/strands_qsr_lib,cdondrup/strands_qsr_lib,pet1330/strands_qsr_lib,PDuckworth/strands_qsr_lib,strands-project/strands_qsr_lib,yianni/strands_qsr_lib,yianni/rtd-dbg,Raziel90/strands_qsr_lib