deleted. (now use select_fams_by_ids.pl)
same as select_fams_by_id.pl, just changed name.
put_min_branchlengths_into_newick subroutine added.
open, 2 param form -> 3 param form.
Now cl argument to specify whether certain clades are required at all.
e.g.  select_from_pruneout.pl ltdcdc 2 2 110 ; '110' means the 1st and 2nd clades
(6 of 7 dicots, 3 of 4 monocots by default) are required to be present,
but clade 3 (Selaginella by default), is not.