Wrong Igs computed in abelian group

[hulpke]

From an error report by Graham Ellis on 3/26/21, the issue ultimately is:

gap> A:=AbelianPcpGroup([3,2,12]);;
gap> m:=MinimalGeneratingSet(A);
[ g1^2*g2, g3 ]
gap> AddToIgs([],m);   # wrong, currently used
[ g1, g3 ]
gap> AddToIgs_Old([],m); # correct, not used
[ g1^2*g2, g2, g3 ]

It seems that the new IGS code given in #51 would resolve the issue.

[stertooy]

With version 2.16, I'm getting

gap> AddToIgs([],m);
[ g1, g2, g3 ]

instead. The difference is likely due to #43.