fixes http create server & http gets/posts

Goes with https://github.com/tessel/firmware/pull/51

On http connections we now try to close and reopen the socket if it errors out.

On http create server we now:
* queue up polling events to check for `accept`
* queue up `._write` events on `net`
* queue up `._write` events on `http`
* lets the cc3k recover if it runs out of memory
We should check if buf is NULL.