t/target.t
Added code to test the output of the summary method.
scripts/find_and_score_crispr_sites.pl
Added option --requestor to allow requestor to be specified for all targets.
Added --requestor to POD.
If --requestor is not set it gets set to 'NULL'. Then the requestor for each
target is one of either --requestor, the requestor column from the input or 'NULL'
in that order.
Added subroutine get_requestor to do this.
Changed option --target_seq to --target_sequence.