Should have some kind of timeout

[evilpie]

A few tests hang in SpiderMonkey and just occupy an agent forever.

Aside: I tried doing something like `--hostArgs="-e 'timeout(3)'", but that doesn't work here because host-arguments are appended after the file. Usually on Linux I think it is more common to pass optional flags before positional arguments.

[bterlson]

I can move the position of host arguments.

I am working on a timeout as we speak but it requires plumbing work. Step 1 is to add a .kill() or somesuch to eshost (it already has .destroy() but 1, it doesn't kill a host if it's busy, and 2, I probably don't want to entirely tear down a browser host). Then a timeout is pretty easy to add into test262-harness.

[bterlson]

Will hopefully finish this weekend, no promises though (tee hee)!

[bterlson]

eshost 3.3 has Agent#stop() for stopping long-running scripts. I have a change in the works to use this capability in test262-harness but realized raw tests always timeout in the browser (or, in the current version, hang) so I'm trying to think of a way to solve this.