Added a warning against implicit hazard levels [skip hazardlib][demos]
Added a warning against implicit hazard levels [skip hazardlib][demos]


Former-commit-id: bfd1e5cc41bbce43fef3d3636adf5595259fbf23 [formerly 217f39703495461d11c777f2d80308d3cd0c2bda]
Former-commit-id: d63527b2206f5f74295e01a12da94e3b47bf14ce
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine