Sort concept's immediate children in alphabetic order.
None = sortchilds(aConcept);
aConcept - type: con
L("con") = getconcept(findroot(),"top");
getconcept(L("con"),"32");
getconcept(L("con"),"3");
getconcept(L("con"),"33");
sortchilds(L("con"));
Before sorting, the children of "top" are ordered 32, 3, 33.
After sorting, the order is changed to 3, 32, 33.