[ENSCORESW-1763] Add a synonym for DBEntry->release to help people find DBEntry versions.

modules/Bio/EnsEMBL/DBEntry.pm

@@ -282,6 +282,24 @@ sub version {
   return $self->{version};
 }
 
+=head2 db_version
+
+  Arg [1]    : (optional) String $arg - value to set
+  Example    : none
+  Description: Alias for release(). The release/version of the external DB
+  Returntype : String
+  Exceptions : none
+  Caller     : general
+  Status     : Stable
+
+=cut
+
+sub db_version {
+  my ( $self, $arg ) = @_;
+  return $self->release($arg);
+}
+
+
 
 =head2 description
 

modules/t/dbEntries.t

@@ -300,6 +300,11 @@ $xref->primary_id('2');
 $dbEntryAdaptor->update($xref);
 my $updated_xref = $dbEntryAdaptor->fetch_by_db_accession('Vega_gene', '2');
 is($updated_xref->description(), 'new_description', 'Xref with updated description');
+is($updated_xref->db_version, '1','DBEntry release/version can be accessed');
+is($updated_xref->release, '1','DBEntry release/version can be accessed by both methods');
+
+$updated_xref->release(2);
+is($updated_xref->release, '2','DBEntry release can be changed');
 
 #
 # 12-14 Test that external synonyms and go evidence tags are retrieved