Paramikojs negotiates with ssh!

It doesn't get all the way because of dependency problems, which I'm fixing one by one.
I had to temporarily use WebSockify's base64 mode for this, [even though I patched that](https://github.com/kousu/websockify/commit/f345e4e86af9bc23bf2470d31688eeefa10f0f54),
since it seems there is a bug in my patch that tricks Firefox into reading payload as header,
in the case of large payload.

For some reason, nodejs's "ws" module does not react the same, even with identical code (see `plain.html`).
Is Firefox more restrictive? Probably. I will need to dig through packet traces to figure out what's up.
MILESTONE: I can run shell commands from javascript

This commit hacks around password login not working
I think maybe paramiko (which is tightly bound to firessh at the moment)
is trying to load ssh keys from disk, crashing, and not reporting the error
anywhere because it happens deep in some callback chain.

Timing is a problem, in general..
Merge branch 'master' of github.com:kousu/ssh.ws