fixed error caused by submitting date_extend param without date; fixed get_parent_organisations error due to RDBO catching param exceeding max permitted length
patched C::Ajax::get_parent_organisations() and corresponding model method to accept flag for practices lookup; create new GP practice allows submission of parent practice id for branch practices
referral_source autosuggest loads only active records for registrtaion and request edit functions; new column is_active on referral_sources table; refactored list_all_screen_tests table to show screen categories
