PrimarySeqI.pm: Avoid using Bio::Root::clone when object
is 'Bio::Seq::LargePrimarySeq' or 'Bio::Seq::LargeSeq'.
This fix fails in t/Seq/LargePSeq.t and t/SeqIO/largefasta.t

Fix conflict:
	Bio/PrimarySeqI.pm
No, really, fix the conflict :P