in translate now strip terminal stop codons from mrna before making Bio::Seq out of it

translateable_seq does still return sequence  with stop codon on the end

script.

genes in chromosomal coords from fetch_by_stable_id

database used for transform is _always_ taken from slice/contig (i.e. not feature or exon)
tidied up a bit in SeqFeature and BaseAlignFeature

Gene start/end/strand/chr_name convenience accessors improved a bit (warning only if gene spans contigs)

slight change to desc string of Slice and RawContig & avoid warning in Slice::get_all_SimilarityFeatures

Lite GeneAdaptor::fetch_by_stable_id and fetch_by_transcript_stable_id now return genes in RawContig coords

renamed Slice::get_landmark_MarkerFeatures to get_all_landmark_MarkerFeatures