multi-line exec

[duralog]

this fixes #12

I tried putting it on my gh-pages so you could try it out first there, but I accidentally made the PR from my gh-pages branch. either way, it works.

---

var lala = 1234;
alert('lalaa');
return "lala"+lala;
> TypeError: alert is not a function

var lala = 1234;
return "lala"+lala;
> lala1234

var lala = 1234;
"lala"+lala;
> undefined

[natevw]

Sorry, I really want to go down the route of trying to parse JS code. For that there are more robust alternatives that do this using what amounts to full-fledged JS compilers.

evel is intended to remain an "as tiny as possible" implementation. Things like #12 may just remain known caveats.

I would entertain doing something like this if it were a minimal change [this patch includes a lot of unrelated stuff] and I could be convinced that it would never cause the sandbox code to be corrupted (For example, do your regexes handle parentheses that occur in strings/comments/etc.?). I'd rather have a hard parse error from the browser's JS engine, than edge cases where some incorrectly-changed source code might still "successfully" execute and return a bogus result.