Add equals() method:

  Arg [1]       : Bio::EnsEMBL::Transcript transcript
  Example       : if ($transcriptA->equals($transcriptB)) { ... }
  Description   : Compares two transcripts for equality.
                  The test for eqality goes through the following list
                  and terminates at the first true match:

                  1. If Bio::EnsEMBL::Feature::equals() returns false,
                     then the transcripts are *not* equal.
                  2. If the biotypes differ, then the transcripts are
                     *not* equal.
                  3. If both transcripts have stable IDs: if these are
                     the same, the transcripts are equal, otherwise not.
                  4. If both transcripts have the same number of exons
                     and if these are (when compared pair-wise sorted by
                     start-position and length) the same, then they are
                     equal, otherwise not.

  Return type   : Boolean (0, 1)

  Exceptions    : Thrown if a non-transcript is passed as the argument.