Removes the entity from all groups it is a member of.
removeAllGroups ()
Returns *
Remove entity from all groups
var entity = new IgeEntity();
entity.addGroup('g1', 'g3', 'g2');
// This will output "['g1', 'g3', 'g2']"
console.log(entity.groups());
// Remove all the groups
entity.removeAllGroups();
// This will output "[]"
console.log(entity.groups());