onend and ondata was cleaning on parser end

Original patch c/o Evan Larkin <evan.larkin.iit@gmail.com>

This reverts commit e2274412.

Build fails on mac

rnewson found a good bug in keep-alive. we were only using the request
headers we send to enable/disable keep-alive but when the server sends
Connection: close we need to close down the connection regardless.

I wrote up a patch the Robert verified makes all his test client code work
now and I also added a new unittest for it.

Leads to lots of builds with out-of-memory.

Updated extensions tests

This patch removes require.async from nodejs.

1. It complicated the code unnecessarily.
2. Everyone uses sync require anyway.
3. It's got a lot of weird edge cases when mixed with sync require.
4. It is many months behind the commonjs spec anyhow.

first step towards building a libnode.a

Simplify and correct test.

Fix by Fedor Indutny.

The REPL needs the full require(); add test for that behavior.

to enable KQueue, rather than deciding based on the compiler version.