more patches to cron scripts - all date subtractions performed on a new time_now() object in ScriptHelpers::date_subtract(), NOT on the local object in case it's used again after the DT subtract() function performed
moved some LIMS::Base methods out to LIMS::Role::Base; new cron mail_reports.pl - shares some methods from LIMS; exempted http requests to Chart methods from authentication to allow mail_reports.pl script to generate charts
