some more quines

16_quine_A_L_FI_FO_duplicate.mol is a molecule which produces in only 3
steps two copies of the 16 bubble quine (in fact a 18 quine which is
disconnected).
3_3_FI_FO_A_L_gives_16_bubble_quine.mol is the initial 4 nodes molecule
which gives eventually the 16 bubble quine.
3_3_FI_FO_A_L_modified_20_bubble_quine.mol is a 6 nodes molecule which
gives a 20 quine which is different than the 20_quine.mol.