new screen_category table; moved screens 'type' col to category_id; modified all screening terms & screening tests admin functions to accomodate new screen_category table; removed ajax validation from screen description & lab test field_label as these use 2 & 3-col unique keys so can't be validated by AJAX; email reports function uses users secure email address as sender; modifed portal_access function to supply SHA1 hash of current date - so failed login not sent back to portal page without explanation; modified mail_reports.pl to use item names instead of table id accessors

added ENV variable DB_SESSIONS to force dev server to use db instead of file store for sessions; moved _update_session_userid flag to top of block in cgiapp_prerun so only have to set it once for both new logins & re-authenication after timeout & removed it from _create_user_profile()

patched search constraints error - date_before/after -> all_before/after + validation definition; changed some instances of User::get_user_details to User::get_user_by_username in controllers; added 'query_args' to get_page() js function in date_constraints.tt to allow eg sort_by params to be passed to date constraint constructors

moved authen_config from lims_config.pl to main LIMS app - CUSTOM callback doesn't work when cfg loaded using Class::Singleton instance; modified idle timeout function to automatically load logged-in username in login screen, so only passwd required, and added link to logout if different user; cgiapp_prerun checks form param username matches authen; added region_code back to user_locations + admin functions

moved login.tt from site to login/default.tt; used authen->is_new_login to redirect to C::Login::hello(); moved code to generate new diagnosis list from LIMS::_create_user_profile() to C::Login::hello(); new db table user_message + DB class