refactored user_workload to allocate 1 unit per request, not 1 unit per specimen; added totals and percentages cdata to user_workload; moved user_workload query back to RDBO from dbix
moved M::Chart::get_sql_with_constraint() and _get_search_constraints() to M::Roles::DBIxSimple for code shart between M::Chart and M::Audit; replaced C::Chart::_get_chart_title() function with __PACKAGE__constraint_title, set in M::Roles::DBIxSimple::_set_chart_constraints()