frappe.model.docfield.get_change_column_query (f, new)
generate change fieldname query
frappe.model.docfield.rename (doctype, fieldname, newname)
rename docfield
frappe.model.docfield.update_parent_field (f, new)
update 'parentfield' in tables
frappe.model.docfield.update_single (f, new)
update in tabSingles
frappe.model.docfield.update_table (f, new)
update table