Add assert_in_array() from Aryeh
Add assert_in_array() from Aryeh

bboyle/testharness.js,jyasskin/testharness.js,RatneshThakur/testharness.js,hallvors/testharness.js,jyasskin/testharness.js,zqzhang/testharness.js,ayg/testharness.js,hallvors/testharness.js