set flag in cgiapp_prerun() to update sessions.userid on re-authentication after a session timeout, as session is deleted & re-created (without userid) - still needs more worksvk_diff
replaced several calls to L::Local::find_home() with call to config instance; removed call to L::Local::Debug from lims_config.pl, as debug() uses config instance, which uses lims_config.pl; model classes get config from config instance instead of constructor passing it in LIMS::model(); general tidy-up
