[devtools] fix a couple issues with xvfb-run xvfb-run didn't quite clean up correctly after itself, because: - dash doesn't run EXIT traps on signals - if we don't run the command in the background, a TERM handler doesn't run until the command exits

sync_schema_props_perms('cw_source', syncprops=False)
if schema['BigInt'].eid is None:
    add_entity_type('BigInt')