deal with no finding crispr pair for qc well
when formatting display of crispr qc we now may not have a crispr pair linked to a well
crispr chromosome, start and end columns are now nullable on the qc table, this is for the cases when we can not link a crispr pair to a crispr qc result
Merge branch 'devel' into crispr_qc_fix
Merge branch 'master' into devel
v0.225

    Deal with crispr qc where well has no valid crispr pair.