small bug fix, should use transcript_id no translation_id in fetch_by_translation_id when fetching
transcript object

some changes from old api which needed introducing here

some changes from the old api which needed introducing here

Updated the sentence that says which version of the core schema the document refers to; used 20 since this is (probably) the release that will be on the new seq_region based schema

( need to read about perl array implementation ... )