Changing to LASTZ

People following the declarations of intentions for the next release (these are sent to announce@ensembl.org) may have noticed that we are releasing LASTZ pairwise alignments instead of BLASTZ ones. LASTZ is written by Bob Harris from the Penn State University as a replacement of BLASTZ, as BLASTZ is now considered obsolete (read the announcement).

This is the first release where we use LASTZ for the new alignments. We will update the previous alignments in the following releases.