defect/de-34 -- emailer validation check failure.

nparcel/emailerbase.py
* factor out the common validate() method into new email base class

nparcel/emailer.py
nparcel/restemailer.py
* base Emailer() class off new class nparcel.EmailerBase
task/ta-nst-011-48 -- enhance the nparcel.table.jobitem.reference_sql()
method to présent scanned ADP détails

nparcel/table/jobitem.py
* updated the reference_sql() method to display scanning ADP details