add test for overwriting accessor properties.
add test for overwriting accessor properties.

toshok/echojs,toshok/echojs,carlosalberto/echo-js,toshok/echojs,toshok/echojs,toshok/echojs,carlosalberto/echo-js,carlosalberto/echo-js,carlosalberto/echo-js,toshok/echojs,toshok/echojs,carlosalberto/echo-js,carlosalberto/echo-js,toshok/echojs